Père Lachaise Cemetery. It's an oasis of quiet and beauty in the city. There are many different above-ground crypts and tombs, and fascinating architecture and sculpture. And empty tombs because descendants refused to pay for their upkeep, so the remains were removed. The landscaping is beautiful. Lots of famous people are buried there, in particular Jim Morrison, Moliere, Chopin, Colette. Go here for some pictures of ten of the graves.
Top 10 Fascinating Graves in Père Lachaise - Listverse
It's free, and you can either download a map or get one from the cemetery office.
(Our dog got kicked out of there once... escorted to the door by a ghostkeeper. He may be the only golden to visit Jim Morrison. No sign at the entrance we used.)