I am happy with this for now... I think I heard of this before but I was never sure what it really meant. the word came up again in a recent Discovery Channel TV Show, about Ancient Greece.
The Greek word meaning; city of the dead normally describes large and important burial areas that were in use for long periods of time.
The Wikipedia page lists over 20 examples all over the world of different Necropleis. I've been to one of the frour they list for Mexico. When I was younger I got to visit Teotihuacan, and all the pyramids there and the temple as well. I never realized (until now) that this was a cementary. Duh! what are pyramids usually for? burial grounds right? Should have guessed that.