Too many bones
Sometimes you can have too much of a good thing. Take bones for instance. The Sedlec Ossuary in the Czech Republic, like other overpopulated graveyards in the past, decided to put the bones to good use and make displays out of their bones and skulls.
The Paris Catacombs are somewhat similar, although not quite as artistic as the Czech effort.
Would probably be quite a good place for a seance. I think you’d get a few crossed lines however – I’m not sure if the otherworldly switchboard would be able to cope.