Ghost town

city depopulated of inhabitants and that often stays practically intact

A ghost town is a name for a city or town in which no one lives anymore. It can happen because of economical reasons (for instance, a town of gold miners who cannot find gold anymore), a natural disaster (a flood, a very long drought) or even a man-made disaster (for example, the nuclear fallout that emptied the town of Prypiat, Ukraine).

Bannack, Montana, USA, a ghost town that is now a State Park.
Craco, ghost town in Italy.

Some ghost towns are kept intact as tourist attractions. For example Craco, in the Italian region of Basilicata, is a destination for tourists and pilgrims, as well as a famous movie set for movies like The Passion of the Christ by Mel Gibson and Quantum of Solace by Marc Forster.