Catacombs in Germany or Austria?

There is catacombs in the basement of the Stephensdom in Vienna. You need to pay extra to visit.

I remember seeing one on the left side of the Rhein, could it have been Bacharach or St. Goar? This was many years ago, next to an old cloister restaurant, where the former monks' bones where stacked. You could try asking if there is one when you visit old churches or monasteries. In German, these crypts could be called just that: Krypta (not quite sure about that) or a term, perhaps out of use, "Beinkeller" or "Beinhaus" (Bein meaning "bone" in this sense) or Ossarium, the Latin word.

I haven't been there, but the Pfarrkirche in Hallstatt has an ossuary.

Hallstatt came to mind for me. It's not really my idea of a catacomb as much as just a lot of stacked bones. When I think catacombs, I think underground passages (like in an Indiana Jones movie). I went to a place in Rome that, I think, was described as catacombs. It was essentially the same thing, a hallway with a series of rooms full of centuries of monks bones, sometimes arranged artistically. Interesting, but not something that inspired the imagination.

I've visited the bone house in Hallstatt, and it's pretty interesting...lots of skulls and bones...probably half of the skulls are painted with flowers or vines (or both – can't really recall)....definitely not catacombs, though, and only good for maybe a 10 minute look around. It's very small...like a small cave or cellar.

I believe there are catacombs in old Salzburg across from a Catholic Cathedral. We wanted to tour it and we were disappointed because on the day we were there, I think it was Monday, they were not open. Sorry I can't be of more help!