Openstreetmap-carto: Add rendering for historic=ruins

[EdLoach]

Neither POI or area/multipolygon ruins are currently rendered. http://www.openstreetmap.org/note/114642 brought this to my attention, as the castle named in the note is already mapped as both POI and multipolygon.

For POI, perhaps just the name rendered, and for areas - well I'll let you pick a suitable colour. The wiki also suggests a lot of ways are also tagged as ruins - perhaps for these render a bit like generic barriers?

[thecrazychemist]

Yes, there is a need for this. historic=ruins should render on the map.

[kocio-pl]

I guess dashed outline (as mentioned here, citing OsmAnd) could work as a visual hint.

[nebulon42]

I don't think that works for historic=ruins. AFAIK OsmAnd uses an icon (shown in the screen) for historic=ruins. A dashed outline makes only sense for building=ruins (see https://github.com/gravitystorm/openstreetmap-carto/issues/1898).

[dieterdreist]

sent from a phone

Il giorno 24 set 2016, alle ore 21:07, Michael Glanznig [email protected] ha scritto:

I don't think that works for historic=ruins.

what s the difference to archaeological site? Maybe we can use the same rendering?

[kocio-pl]

What about this icon of ruined castle, proposed for Osmic by @MaestroGlanz:

https://github.com/MaestroGlanz/osmic/blob/b6f0eaa85eedfc453e5c9b8b19ca8d1d3a89e54d/tourism/castle-ruins.svg

[kocio-pl]

Example rendering on z17:

[polarbearing]

The separate shape above is implausible, what is it supposed to be?

[kocio-pl]

I agree that ruined castle icon is not working in practice. I guess we can use the idea of decomposed shape for something simpler, like house.

[MaestroGlanz]

It is directly derived from the castle icon. I could change it to a version where the parts are joined.

[kocio-pl]

Please try, we're still looking for something good enough.

[SomeoneElseOSM]

FWIW (different map) for nodes I went for the name and a dot, in a "historical" colour https://map.atownsend.org.uk/maps/map/map.html#zoom=17&lat=53.429972&lon=-1.26303 and for ways the name if present and a "not quite a building" colour https://map.atownsend.org.uk/maps/map/map.html#zoom=19&lat=53.122449&lon=-1.853998 and https://map.atownsend.org.uk/maps/map/map.html#zoom=20&lat=53.2699203&lon=-1.989286 .

The actual colours won't transfer to OSM Carto, but I'm not convinced you need a "characteristic" icon - the name normally describes the thing well enough.

[MaestroGlanz]

I have two other suggestions here:
https://wiki.openstreetmap.org/w/images/a/a4/Building_ruins_generic3.svg
https://wiki.openstreetmap.org/w/images/c/cb/Building_ruins_generic2.svg

You can check the appearance on
https://wiki.openstreetmap.org/wiki/User:MeastroGlanz#Icons_I_created

I used 16px grid. At least, I think so.

@kocio-pl @polarbearing

[kocio-pl]

Still not recognizable for me at 14 px.

[MaestroGlanz]

I created other versions:
https://wiki.openstreetmap.org/w/images/7/76/Building_ruins_generic4.svg
https://wiki.openstreetmap.org/w/images/6/62/Building_ruins_generic5.svg
https://wiki.openstreetmap.org/w/images/6/62/Building_ruins_generic6.svg
https://wiki.openstreetmap.org/w/images/5/5d/Building_ruins_generic7.svg

All together on https://wiki.openstreetmap.org/wiki/User:MeastroGlanz#Icons_I_created

Do you have any suggestions of mixing some of the ideas?

[MaestroGlanz]

I prefer version 3 the most.

Btw. are there any icons, which should be created?

[kocio-pl]

Nice try, but none of them work for me at 14px (32 px would be OK). I was thinking about solid, easy to recognize shape like a simple house as a base.

[PontiacCZ]

I like Building_ruins_generic6.svg... and Building_ruins_generic4.svg as well.

[kocio-pl]

Btw. are there any icons, which should be created?

Sure, you may for example look at #131, #152, #2518, #1870, #958, #2856...

[kocio-pl]

@PontiacCZ Try to look at 14 px version only, because that's the only thing the user will see.

[PontiacCZ]

Yep, that's what I actually did, I compared icons in the "Icon original size" row on the summary page and my Firefox tells me they're 14 px wide.

Well, the more I look at the variants the more I like (Building_ruins_generic6.svg) - the concept of one fallen tower and the other one still standing is pretty clear for me to understand it as ruins.

I am not sure, MastroGlanz, what you mean by version 3 - is it (Building_ruins_generic4.svg)? Pretty nice as well, for me on the 2nd place.

But any of those would be better than none.

BTW kocio-pl, you have mentioned that "one of them work for me at 14px". Which one is it?

[kocio-pl]

I meant "none" - sorry for the typo.

6 is a nice concept, but the details are too small for me, so it looks just like 2 rectangles, with no connection to buildings.

[MaestroGlanz]

@PontiacCZ Have a look at the post from 4 days ago. There is 2 and 3.

[MaestroGlanz]

I added two further versions:

https://wiki.openstreetmap.org/wiki/User:MeastroGlanz#Icons_I_created

I prefer version:
3, 10, 6, 4, 2 in that order.

[kocio-pl]

For me 8 looks quite promising as a base:

• the window should be bigger
• the top should be wider/bigger
• instead of lying part there should be "ruins" pixels (similar to 1-3 design, but without door entry)

[Tomasz-W]

What about "ruined" museum icon?

[MaestroGlanz]

I also have a new suggestion.

[Tomasz-W]

@kocio-pl Can you review the proposals?

[kocio-pl]

None of them work for me. I was thinking about something like simple manor/house with decaying one side (just like this: https://github.com/gravitystorm/openstreetmap-carto/issues/331#issuecomment-331642349).

[Tomasz-W]

You mean manor icon https://github.com/gravitystorm/openstreetmap-carto/issues/744#issuecomment-370141077 with ruined right side, yes? Did I understand correctly?

[kocio-pl]

Yes. The castle icon had two problems - it was too distinctive (while ruins may be very generic and not even really historic) and it has not too regular shape, so it's not easy to see the progression of decay, and it looks just like a tower with something small attached. Otherwise the idea still appeals to me.

[kocio-pl]

I reworked manor icon, but this doesn't have to be any of them - just generic house could be even better.

[Tomasz-W]

simple manor/house with decaying one side

@MaestroGlanz Can you try to make it?

Heres SVG's with manor shapes for a start:
https://github.com/kocio-pl/openstreetmap-carto/blob/9cd636602fd4faf7b1546ae4fc091b936106cbca/symbols/manor.svg
https://github.com/kocio-pl/openstreetmap-carto/blob/761d4fe24c5dc76f833c103a3611ad8c18083acc/symbols/manor.svg

[MaestroGlanz]

I added number 12 and 13:
https://wiki.openstreetmap.org/wiki/User:MeastroGlanz#Icons_I_created

based on the manor icon

[Tomasz-W]

Thanks!

I'm posting preview here:
(12)
(13)

[kocio-pl]

13 is quite close for me. It has similar problem as a castle - it has doors hole in the middle, so the decay is not that obvious and the right part may look like something added, not the remains. What if the doors are there (halftone could help)?

12 is a clever new idea, but it's not clear for me at 14 px. What about others?

I tend to think that original proposition could work, but the tower should be complete to be recognized at this resolution. The idea was good, but it was not well suited for such a small matrix, it was too subtle and even didn't use all the available width. So my take would be more schematic and with bigger elements (15 looks better for me):
14)
15)

[kocio-pl]

Or something more generic than a destroyed fortress:
16)

[MaestroGlanz]

Right now, I would settle for @kocio-pl 's 15. We can change it, if we come up with something better. But since there hasn't been something better in a long time yet, I guess it wont come soon.

[Tomasz-W]

Remember, that historic=ruins tag isn't used only for very old buildings like temples, palaces or manors, but also for abandoned factories etc. A destroyed fortress icon may be confusing then. What about more universal icon like a broken square?

[dieterdreist]

sent from a phone

On 1. Jul 2018, at 13:14, Tomasz Wójcik [e-mail] wrote:

Remember, that historic=ruins tag isn't used only for very old building like temples, palaces or manors, but also for abandoned factories etc

+1, without the ruins subtag or something similar you don’t know what it is (hence shouldn’t be rendered just by that tag alone)

[Tomasz-W]

Fresh icon proposals:

• (building rubble)
• (broken brick)
• (broken building)

[jragusa]

On french and swiss topographic map, abandoned buildings are displayed as building without filling. This is probably IMO a more appropriate way to identify ruins:
1/ we can use icon to describe the former function of the ruin (castle, factory, archaeological site...)
2/ it's more suitable for abandoned houses for which there is no icon
3/ ruins are not necessarily important landmark (sometimes only the basement remains) or at least does not need to be highlighted with an icon
4/ this allows to describe that the building is incomplete (no filling): roof or walls are missing

Example from french map and swiss map

[Tomasz-W]

@jragusa It's not a solution for this issue, because ruins are often mapped as a node in the middle of rubble. We need some icon to solve it.

[Adamant36]

@Tomasz-W, if we are at that point and you want to provide .SVGs of your broken building icons, I would be willing to test them in an attempt to get this moving again.

[Tomasz-W]

It's always nice to see a test rendering, even if an icon is not promising.

Gist link: https://gist.github.com/Tomasz-W/1b20e25696daf714d9593552556916a1

[Adamant36]

Location One

Icon one

icon two

icon three

Location Two

icon one

icon two

icon three

[Tomasz-W]

1 or 3.
I think it should be in some dark-red colour (like warning), as these places are usually dangerous, darken(@military, 40%) used for landuse=military labels might be an option.

[Adamant36]

Ok. I'll give it a try. I like 1, except not all ruins are buildings. So three at least has the advantage of being more generic.

[MaestroGlanz]

Since you dont like my suggestions, definitely Number 2. Number 3 is not self explaining, number 1 has particles in it, which is never a good idea on the map.

[MaestroGlanz]

@Tomasz-W No, I oppose. It should be definitely the colour of sights and archaeological sites, since it is related to them. We might use two icon colours. One for sight type, one for ordinary ruin. But ordinary ruins shouldnt be rendered at all. At least not that way.

[dieterdreist]

sent from a phone

On 18. Sep 2018, at 09:06, MaestroGlanz [e-mail] wrote:

One for sight type, one for ordinary ruin. But ordinary ruins shouldnt be rendered at all. At least not that way.

according to the wiki, profane ruins (without historic significance) should be tagged with lifecycle tags and not with historic=ruins

[Tomasz-W]

profane ruins (without historic significance) should be tagged with lifecycle tags and not with historic=ruins

Describing exactly, they should be tagged with ruins=yes, so I think we should consider using the icon also for this tag.

[polarbearing]

Icon 1 (with the loose stones) is most recognisable to me.
I'm against a warning colour, in particular for the historic ones. They could actually be quite safe to walk around.
man_made grey would be most suitable.
Archaeological sites use cultural(amenity)brown, though I'm not so sure about the cultural aspect of the historic ruins.

[jragusa]

Describing exactly, they should be tagged with ruins=yes, so I think we should consider using the icon also for this tag.

I'm not sure that the final state is more important than the initial purpose. If you have ruins of a castle, do you think that ruin is more important than the castle tag ?

[Tomasz-W]

If you have ruins of a castle, do you think that ruin is more important than the castle tag ?

No, of course not :) , but if there are ruins of simple building=yes, it would be nice to mark them by dedicated icon as they might be local small attraction. It would be very useful for all urban explorers.

[Adamant36]

@MaestroGlanz, I don't think any of us had anything particular against your suggestion. Its just called testing stuff. As @Tomasz-W said "It's always nice to see a test rendering, even if an icon is not promising." Also, can you give more detail about the whole "particles are bad" thing? I'm interested to know why its an issue. The icon seems fine to me, but I could imagine a scenario where the particles could potentially blend with something behind them so as to not be visible. I'm no expert on that though.

[SomeoneElseOSM]

but if there are ruins of simple building=yes, it would be nice to mark them by dedicated icon

We don't mark regular buildings with an icon, so I'm not entirely convinced that ruined buildings deserve them?

In a different map style I did display these ruins as per other "not quite a building" buildings (slightly lighter than a dark building colour). Maybe something similar will work here?

[dieterdreist]

2018-09-18 9:33 GMT+02:00 Tomasz Wójcik [e-mail]:

profane ruins (without historic significance) should be tagged with
lifecycle tags and not with historic=ruins

Describing exactly, they should be tagged with ruins=yes, so I think we
should consider using the icon also for this tag.

I would not add an icon for every ruin, only the significant ones.
"lifecycle tag" intended the ruins-prefix like ruins:building or similar
prefixes, e.g. abandoned:building.
I thought there is general agreement to discourage tags like abandoned,
disused, razed, ruins, etc. = yes/no because they bear a much bigger risk
of misinterpretation. In this style we should not support ruins=yes to not
encourage this bad mapping style.

[Adamant36]

I agree with Dieterdreist. I think if there's rendering for things like ruin=yes, which is more about the state of something then its cultural/historical significance, it risks the rendering being added to old dilapidated houses etc that might be ruins in the definitional sense, but have reason for being rendered in a special way on the map. The same goes for the life cycle prefix. Its added to a lot of things where the life cycle is either in flux or not worth noting for any unique reason on a general map.

[Tomasz-W]

Just for the note - the output is: icon no. 1. in _man_made-grey_ used only for historic=ruins

[jidanni]

Apparently currently

abandoned:building=yes
building=ruins

is not rendered. One could imagine hiking for hours, never knowing there was a ruins just over the ridge, until after returning home.

[jeisenbe]

All values of building= except building=no are currently rendered, but we don't render abandoned:building=.

[SomeoneElseOSM]

One could imagine hiking for hours, never knowing there was a ruins just over the ridge, until after returning home.

I'd be very surprised if someone was "hiking for hours" armed only with a copy of this (very general) map style. I'd expect that they'd use something (perhaps also based on OSM) that showed them useful features such as this.

[jidanni]

@jeisenbe OK it finally showed up. But it looks just like a plain building(=yes)!

[jidanni]

Today

historic=ruins
ruins=tower

doesn't render. Ah,

historic=archaeological_site
ruins=tower

does! OK see you guys later.

[dieterdreist]

there are also other competing tags for ruins. For example, in the context
where I am mapping, most
historic=ruins are better represented with
historic=archaeological_site (and further tags).
These 2 are incompatible (use the same key), and I see no benefit of
encouraging "ruins" over "archaeological site".

Another alternative is lifecycle tagging:
ruins:man_made=tower
ruins:building=tower
etc.

[jidanni]

(I would have thought an archaeological_site would contain various ruins, like hospital_grounds contains various (hospital_)buildings, and school_grounds..., resort_grounds...)

[DujaOSM]

Six years after the issue is opened, a lot of quibbling about icon shape, and the feature still does not render.

I agree that historic=ruins is largely coterminous with historic=archaeological_site, so it would make sense to use the same or similar style. Or hash out the issue on the wiki or the mailing list. But please, whatever, give us something. Perfect is the enemy of the good.

[kocio-pl]

I guess that using pattern (for example something like simple "x") over standard building rendering might work, to not make this look too important. What do you think about it?

[DujaOSM]

According to taginfo, the tag is about equally applied to points and ways, so we need something that works for both. Either of the options in #issuecomment-422261781 works for me.

[imagico]

For info:

• historic=ruins: 117k uses, 20k in combination with building=*, 4k with historic:civilization=* as differentiating tag.
• historic=archaeological_site: 129k uses, 86k with site_type=* as differentiating tag, 29k with historic:civilization=*.
• ruins=yes: 79k uses, 50k in combination with building=*
• historic=yes: 80k uses, 29k in combination with building=*, 18k in combination with military=*
• historic=building: 48k uses, most not ruined most likely
• historic=castle: 46k, 4.8k in combination with ruins=*
• ruins:building=*: 2.5k

See also https://github.com/gravitystorm/openstreetmap-carto/issues/4238#issuecomment-718144031.

The semantic boundaries between most of the mentioned tags are fairly poorly defined in both practical use and documentation.

[dieterdreist]

to add to Christoph's datapoints:

building=ruins 98k
building=collapsed 78k

While both tags are not in line with the general building definition, they
are also both in notable use.

[kocio-pl]

We don't render nodes for buildings, so this might also be the same.

Since there are so many different tagging schemes, it might be good to start with discussion on tagging first and make some conclusions.

[DujaOSM]

May I kindly ask that we solve the original historic=ruins problem through this bug as originally conceived (as a relatively well-defined object), and decide what to do with other sorts of building= tags later?

[jeisenbe]

@DujaOSM - the other tags mentioned above in these comments (https://github.com/gravitystorm/openstreetmap-carto/issues/331#issuecomment-726030470 and https://github.com/gravitystorm/openstreetmap-carto/issues/331#issuecomment-726030470) are significant because they overlap with the meaning and use of historic=ruins, as used by mappers.

One of the most important goals of this map style is "It's an important feedback mechanism for mappers to validate their edits and helps to prevent unfavorable fragmentation of tag use.” - and also "Being understandable and supportive for mappers - To serve as feedback for mappers and encourage correct mapping...” See https://github.com/gravitystorm/openstreetmap-carto/blob/master/CARTOGRAPHY.md

Because of these goals, this style should only render tags which are used in a relatively consistent way, and which are the “de facto”, established way to tag a certain real-world feature. When there are 2 or more ways to tag the same feature, as in this case, we need to wait until mappers and the community decide on which method should be supported, as shown by current usage in different countries.

[dieterdreist]

sent from a phone

On 12. Nov 2020, at 18:24, Joseph E [e-mail] wrote:

When there are 2 or more ways to tag the same feature, as in this case, we need to wait until mappers and the community decide on which method should be supported, as shown by current usage in different countries.

historically significant ruins are always archaeological sites, and this style tries to avoid rendering several tags with the same meaning. For other ruins we would want a different rendering anyway.

[DujaOSM]

historically significant ruins are always archaeological sites, and this style tries to avoid rendering several tags with the same meaning. For other ruins we would want a different rendering anyway.

I disagree. I've always interpreted a historic=archaeological_site as something known to have undergone a documented archaeological research, and possibly still marked as such in situ, with a information board or a fence.

Historic=ruins is used for ruins of lesser, former or unknown archaeological interest, but which are nonetheless important local landmarks. I cannot think of a better tag for several objects I mapped recently, e.g:

https://www.wikiloc.com/hiking-trails/fruska-gora-popovica-okretiste-raskrsnica-borove-sume-vaga-raskrsnica-borove-sume-jezero-popovica-o-29555178/photo-18887728
Remnants of quarry cable car station, abandoned since 1920s. Important landmark for hikers. Worked around using man_made=tower.

https://www.wikiloc.com/hiking-trails/ps-fruska-gora-170205-crveni-cot-sajlovac-gradac-potoranj-stranputica-tancos-krug-16339306/photo-10245666
Mapped today. Late Roman-period military outpost hidden in a remote forest. Could perhaps apply archaeological_site, but I do not know about any excavations.

https://fruskac.net/en/locations/misc/old-church-saint-george
Walls of a late medieval church.

Historic=ruins is documented in OSM wiki, supported as an iD preset, and, with near 150,000 objects, it is one of most popular tags not rendered on Carto. And I don't think those are going away anytime soon.

[MaestroGlanz]

I made 13 suggestions here. I think, there should be a one fitting:
https://wiki.openstreetmap.org/wiki/User:MeastroGlanz

If you want another one, another style, let me know.

[jeisenbe]

These three objects are quite different: 1) "Remnants of quarry cable car station”, 2) "Late Roman-period military outpost hidden in a remote forest”, 3) "ruined late medieval stone church”. Consider that the last could also be tagged abandoned:building or abandoned:amenity. I’d suggest discussing how to tag these on a more appropriate forum, such as help.openstreetmap.org or the Tagging mailing list.

[DujaOSM]

A 40-story skyscraper, a 10,000 m2 shopping mall and a backyard shed are also quite different objects, yet we permit tagging them all with building=yes. Conceptually, historic=ruins are not much different, "here are the ruins of a rather old object", and one can apply other tags to describe them closer.

I do read (but do not participate in) _tagging_ and _talk_ mailing lists, and, with respect, I don't remember anything ever solved there. I think that moving discussion to another forum would be a good way to not solve it for another 6 years. With over 100,000 uses, documentation in wiki and support in iD, I believe mappers have already "voted with their feet" about the issue.

Consider that the last could also be tagged abandoned:building or abandoned:amenity.

It certainly could, but that would not render in Carto either.

[dieterdreist]

sent from a phone

On 13. Nov 2020, at 09:49, DujaOSM [e-mail] wrote:

A 40-story skyscraper, a 10,000 m2 shopping mall and a backyard shed are also quite different objects, yet we permit tagging them all with building=yes.

we do not advocate or encourage tagging them the same

[DujaOSM]

we do not advocate or encourage tagging them the same

Certainly. But we render them nonetheless.

[imagico]

@DujaOSM - the meaning of building=yes is pretty well defined and it is used with high consistency according to this meaning (crappy AI based imports aside). Yes, it is a broad tag, but that is not a problem and that is neither the problem why historic=ruins is currently not rendered.

If you think historic=ruins is a well defined tag consistently used according to this definition we invite you to present this view here. Above in https://github.com/gravitystorm/openstreetmap-carto/issues/331#issuecomment-726340221 you indicated that in your view the difference between historic=ruins and historic=archaeological_site is one of significance, notability and on-site documentation. Verifiability issues with that aside - if this is the consensus delineation between the two tags that should be (a) documented on the wiki and (b) confirmed to be actually reflected in use of the tags in the database.

[DujaOSM]

@imagico I'm afraid you're asking for shrubbery. How can I prove or disprove that historic=ruins is "consistently used according to this definition" except by data mining thousands of objects and comparing them with real-world objects that I'm not familiar with? All I can do is to quote the wiki and hope that the text has been forged by consensus and reasonably followed by mappers:

The tag historic=ruins is used with ruins that are of historic importance, where it is not possible, or not appropriate, to be more specific about the type of structure that is now in ruins.
historic=ruins is a generic description, that records only a limited amount of information. More specific approaches are preferred whenever it is possible to describe the original type of structure that is now in ruins. To some extent, contributors can use alternative forms to suggest the degree to which a structure is ruined. Although they both provide similar information, a form such as historic=ruins,ruins=castle suggests a structure that is mainly in ruins, while a form such as historic=castle,ruins=yes suggests a structure that still appears much like a castle.
Generally, most older ruins can also be described with historic=archaeological_site and its subtags.

Besides, what this has to do with rendering or not rendering in Carto? I really did not come here for _that discussion_, but to report an issue that irked me for a while (and I found this one by searching). In my opinion, the default and flagship map style of the project ought to render all reasonably common and on-wiki documented map features, regardless of any ongoing disagreement about the exact scope. I don't really care which visual style is applied as long as the object is somehow rendered on the map.

[imagico]

In my opinion, the default and flagship map style of the project ought to render all reasonably common and on-wiki documented map features, regardless of any ongoing disagreement about the exact scope.

Well - that is not going to happen as @jeisenbe explained. Again - we invite you to argue for feature addition under the premises and goals of this style but if you don't want to do that it will have to wait until someone else does.

Yesterday i presented some numbers from taginfo (supplemented by @dieterdreist) that could be used (in combination with the discussion in #4238) as a starting point for sorting out how different tags in the historic/abandoned/ruined structures field are practically used. This is all no rocket science, taginfo and overpass turbo are your friends here (also geofabrik's regional taginfo instances can help you with analyzing regional differences). Sometimes you might need to run a planet file through osmium for some more detailed stats. And yes, geographic knowledge is useful here as well as the ability and willingness to discuss tagging with other mappers on the usual channels.

You write:

I don't really care which visual style is applied as long as the object is somehow rendered on the map.

Well - we do and we take our responsibility to produce a style of decent cartographic quality and pursuit of our documented goals seriously. So our perspectives here differ. If that causes incomprehension and annoyance on your side i can relate but this does not change the situation in substance.

[DujaOSM]

"An engineer is a person that makes something work. An expert is a person that can thoroughly explain why something cannot work."

Going back to my engineering business, then. Sorry for wasting your time.

[dieterdreist]

Am Fr., 13. Nov. 2020 um 17:09 Uhr schrieb DujaOSM <[email protected]

:

Going back to my engineering business, then. Sorry for wasting your time.

although this was funny, I have been left with the impression that you are
frustrated about the outcome of this discussion. I am sorry for this. I
have myself been asking for rendering this tag many years ago, but from my
current understanding, it should not be rendered, because it is not applied
consistently, and because the case that is literally described in the wiki
"The tag historic=ruins is used with ruins that are of historic importance,
where it is not possible, or not appropriate, to be more specific about the
type of structure that is now in ruins." is completely covered by
historic=archaeological site. Just nest archaeological sites if you have
one inside the other.

Also note that "historic importance" is a subjective judgement, and not
useful as a requirement because it will only lead to edit wars and will be
hard to decide about. "Significance" is already determined through the
mapper (if she thinks something is not sufficiently significant, she will
not map it). Our main criterion is "verifiable on the ground", "importance"
on the other hand seems to open a way to dismiss things that are verifiably
existing on the ground, as "unimportant".

[DujaOSM]

We can argue all day about differences between historic=archaeological_site, historic=ruins, building=ruins and abandoned:building. The fact of the day is, there are some 200,000+ verifiable ruins on the ground, and thousands good-faith mappers of who know or do not know about their importance and other details have entered those in our database, but we do not find those worth rendering because shrubbery.

Accidentally, I've just stumbled upon this:

Anders Torger wrote Sat Nov 7 11:21:26 UTC 2020
And now to the most important point, whether one likes it or not,
OSM-Carto as being the face of OSM and the most commonly used style, is
the de-facto reference and driver of features and tagging. If OSM-Carto
doesn't support basic cartography features many mappers won't be
motivated to tag for that, and then the cartographic styles will have
less information than they need to make good maps. OSM-Carto due to its
limited rendering capabilities also make casual mappers tempted to "tag
for the renderer" just to get results, which for example can mean that
villages are upped, and thus the cartographic style will get fed with
incorrect information.

This morning I found out the location of those Roman-era ruins so I wanted it to map them and show to my friends, so that's what brought me here. I'm now going off to tag those for the renderer. Building=whatever will do, I suppose.

[dieterdreist]

just go with "historic=archaeological_site"