This was from the Bone Church in the Sedlec Ossuary in the Czech Republic. There were another 20,000 skulls on the other side of the church, as well as other parts of the body used as decorations (collarbones, pelvises, etc.). I won’t lie when I say that it was a bit creepy being in there and seeing all these skulls and whatnot lying around, especially since it was starting to get dark outside.
Travel perspective, tales, and advice 
Ah, any explanation for the creation of this, er, oddity?
Yeah. Basically the plague hit the region hard, and they had a lot of dead bodies lying around and not enough space. Therefore, the priests of the church decided to hire a local woodcutter to deal with the bones. Thus, he was the world’s first interior church designer to work with bones.