In which country is the ossuary (chapel) in Sedlec, decorated with human bones and skulls?

Let the dead rest in peace. Don't use them for decorations.

You know, you live your life and take in all the beauty and happiness that this existence can provide, and for some reason after you pass away, your bones end up in a place like this and someone charges dough for other people to see them. Weird.

there's a similar place in Rome - I found it deeply moving.

its artistic but thinking its human skulls and bones its scarry how it came to be (how did they produce all those bones)

I've visited there. it's a bit creepy but worth the visit.