How does one tag historic archeological ruins of earthwork fortifications :) correctly?

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Hi, I’m a bit at a loss on how to tag some several hundred years old fortications (example1, example2, example3; best viewed with LIDAR as background/imagery https://owsproxy.lgl-bw.de/owsproxy/ows/WMS_LGL-BW_ATKIS_DGM_025_Schummerung?FORMAT=image/png&TRANSPARENT=TRUE&VERSION=1.3.0&SERVICE=WMS&REQUEST=GetMap&LAYERS=Schummerung_DGM_025_BW&STYLES=&CRS={proj}&WIDTH={width}&HEIGHT={height}&BBOX={bbox} ). These are earthworks (ditch and wall), nowadays often overgrown and somewhat eroded unless maintained by some organization. In LIDAR images and OTG they are clearly visible, but most don’t look like much OTG.There are typically no remnants of buildings. Some are ramparts (earthen ditch and wall), i.e. line structures, some sonces (areas), often combined. I guess if one started digging one might find some artifacts, too, which might qualify them as “archeological sites”. Examples 2 and 3 are part of a large defensive system from the 17th and 18th century (some are based on older fortifications but “modernized” in that period. According to “the books”, there are ~100 known sites stretching across >200km. There are several in the area of examples 2 and 3.

How should one tag these structures:

historic=fortification OR historic=archaeological_site + archaeological_site=fortification (but archaeological_site is defined as an area so +area=no for ramparts only?)

fortification_type=rampart (respectively sconce)

defensive_works=earthwork - or is that redundant with fortification_type?

If line-like ramparts are part of a larger fortification with a sconce - should they somehow be connected in a relation (for which there might be no verifyable name and several have the same name that is also used as a class name for the whole set of sconces of this type in the region)?

ruins=? - earthworks don’t make much of a ruin

Would one need extra tags for the ones kept up as historic monuments or touristic attractions?

Should one place the object lines on the wall or into the ditch or surround both as an area, the latter being less clearly defined than ditch and wall and not visible OTG? How would you connect them (if at all) to define the larger system of defensive structures? Would that be a regular relation?

How about trench systems like this one? I asked some locals but they did not know they even existed. Yet, the name of the guidepost “Pulverbuck” on the path north of it, meaning powder hill, suggests that they probably once were part of a larger structure.

Thanks for your help.

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OpenStreetMap is not a LIDAR sleuthing project. If there is something on the ground but it looks just like an overgrown earth mound, and you need LIDAR and reference books to guess that it must have been some sort of historical structure, keep your guesses to yourself rather than publishing them as fact in OpenStreetMap.

An archaeological site is a site where archaeologists are at work, or were at work; the mere suspicion that if one started digging one might find artifacts does not make something an archaeological site.

If there are individual things that can be detected on the ground you can tag them but do not group them in relations or map any assumptions about how these things might have formed a larger structure if that structure is not in place any more. OpenHistoricalMap is the project where you want to do things like that.

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Maybe that wasn’t clear: I’m not guessing. These are known structures, some with exhibits and markers, many documented also on other maps, some with existing names, websites, infoboards and even guided tours to them. It is not a question if and what it is but how to tag them. For some old fortress or citywall ramparts, towers, etc. are also marked individually and grouped.
The roman limes is mapped even if you wouldn’t recognize it on site in many places unless you knew. LIDAR just helps to identify the outline correctly (I don’t own a GPS device with sufficient accuracy in a forest). Your answer is not particularly helpful towards this and I just wonder what might be wrong to look up a book to learn more about something I see OTG.

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Your examples are currently mapped as, respectively, a rampart, a sconce, a more modern sconce. They’re mapped as standalone features, which is pretty common for this sort of thing. For example, see this part of the landscape around Stonehenge. There’s a whole nested series of related features there, but those relationships aren’t in OSM.

I wouldn’t worry too much what the wiki has to say about things in the “archaeological” area, and instead use taginfo, both the international one, and also more local ones.

Also, you might be interested in seeing which projects process these sorts of features.

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I’ll have a look into those projects, thank you!