A process of decrepitude and disrepair is known as Urban Decay. Once a fully functional live city, or some part of city is now an abandoned land.
A good example to illustrate would be Chernobyl, Ukraine. Where a devastating nuclear accident occurred on 26 April 1986 at the Chernobyl Nuclear Power Plant. Chernobyl is recently opened for hungry tourists and journalists. These photographs give some sort of chills, as its quite a time when no one have lived there and these abandoned lands are truly amazing.