These are all over the place in Norway (as are they everywhere else, presumably!)
When we moved to the island we currently live on, our address was in a road called 'Solsteinen' (The Sun Stone), but I didn't think anything of it until I realized that the roughly hewn stone serving as the property limit marker was juuu-uuust touched by the sun on Winter Solstice. Aha.
A quick call to the local archaeologist confirmed my suspicion - 'Oh, so you're the new resident there, I'd planned on being in touch - that stone monument has been there for more than 2000 years, is A-listed and please, whatever you do, don't do anything with it. Seriously.'
We also have these in Germany, in the region where I live it which is North Rhein Westfalis they are quite a common thing actually. Strongly recomment people check it out if they pass by here some time
> as are they everywhere else, presumably!
They aren't "all over the place" in the US, and I certainly don't have a local archaeologist that I can just call up.
FWIW: The Northeastern US is quite recent with human presence. It wasn't settled until after the last ice age. Pretty much anything old is celebrated because there is so little of anything old.