Thanks for the amendment on my description of the disease, though I didn’t mention that it went through skin, just that it took over muscles, tendons, etc.

Of all these places, Kunstkammer in St. Petersburg was the most unbelievable, but the Bone Chapel is pretty breath taking. I’d love to read that story you mentioned. I’ll see if Google provides.

Also Fibrodysplasia Ossificans Progressiva isn’t bone protrusions through muscle and skin, it is actually the soft tissue turning into bone. The horrific nature of this is well seen in skeletons of its victims where muscle has been ossified and permanently frozen in place.

That last place looks genuinely amazing, I have seen that quote before, I think it’s from a medieval poem/song called the Dance of Death which tells of a party going astray on horseback and coming across skeletons singing those lines and dancing in the forest.