How to tag relations such as Seven Summits or Seven Wonders?

I would like to have on the map relations which gather POI in certain categories. Good examples are: https://en.wikipedia.org/wiki/Seven_Wonders_of_the_Industrial_World

or: https://en.wikipedia.org/wiki/Seven_Summits

or: https://en.wikipedia.org/wiki/Ch%C3%A2teaux_of_the_Loire_Valley

However i have absolutely no idea what kind of relation this should be. Any help?

Dont put those into a relation. Relations are not categories.

case above is different than cathegories in the article you link. U can can use overpass and get all paths in south wales but no query will get you seven summits. I believe this is valid relation. Just dont know how to tag it.

No, this are perfect examples of relations we don’t want in OSM. See http://wiki.openstreetmap.org/wiki/Relations/Relations_are_not_Categories

They kind of have a point though: That page’s main argument against category relations is that you can use a query instead. That’s not the case with any of the various “Seven Wonders”, for example. (Although the Seven Summits could be identified using an overpass query.)

Then again, one problem with “The best X” style lists is that they are somewhat arbitrary. For example, the “Seven Wonders of the Industrial World” are not really an agreed upon concept as far as I know, but mostly the creation of British TV. So we are kind of getting into “the best hiking routes according to Foobar Guide” territory here.

Yes, “Seven Wonders” seems to be an subjective list created by the BBC. The topics which the TV series treats should be added into Wikidata. I don’t think that we should add those kind of informations into OSM.

The Seven Summits can be also retrieved from Wikidata: https://tools.wmflabs.org/reasonator/?q=Q208126&lang=de

Where is the border between universally agreed on lists (Snow Leopard Summits for example) and arbitrary lists?

https://en.wikipedia.org/wiki/Snow_Leopard_award

I really think that this kind of data will be a nice way to enhance OSM functionality. I totally agree with arguments on categories. We do not want “Best clubs in London” relations, really. But in the same time i have a feeling that we miss some opportunity here to add valuable information to the map. If not relations - what?

As far as i underestand Wikidata does not include geolocation. Do i miss sth?

Sorry for getting back to this, but i still have issues and questions. What about:
https://en.wikipedia.org/wiki/Struve_Geodetic_Arc

Do you think it’s good idea to link those points as relation? Note, that this is one UNESCO World Heritage Site, just in different locations.

It’s something that was discussed at length in the German OSM community, particularly the forum. Have a read of that to get both sides of the topic.

There’s no hard-and-fast rule, but generally speaking, if you can get the information you need from e.g. Overpass, there’s no need to create a relation. In the case of the “Struve Geodetic Arc”, it would seem that tags on the constituent observatories would make sense. I’d have a look at how other UNESCO World Heritage Sites are mapped, and see if you can get anything useful from there, and of course ask the people who mapped the things already in OSM, such as https://www.openstreetmap.org/way/37558758 for their opinion too.