Earlier quoted context omitted.
Excuse me sir, but now you're making it look like they are ubiquitous. Pretty sure that's not the case either. So I appreciate this post, first time I hear of this.
If you want to see one of these places, I can recommend Sedlec Ossuary in Kutna Hora / Czech Republic. I contains about 50,000 skeletons, which basically make up all the interior decoration. It is interesting how you get used to being surrounded by skeletons. https://en.wikipedia.org/wiki/Sedlec_Ossuary Edit: They also have a very nice gothic cathedral, a modern art museum and a silver mine that was turned into a mus…
The other cathedral has the most bizarre roof, one third roof, one third domes, one third bell tower, and a wonderful organ well worth the visit, and many beautiful frescoes depicting the work that made this place so rich : silver mining.