A kind of urban planning, but with a twist...

[Michele Zone]

Secret Complex Exists Underneath Belgrade

The 2-square-mile complex — dubbed a "concrete underground city" by the local media — was built deep inside a rocky hill in a residential area of Belgrade in the 1960s

Semi-relevant to current events as well:

The complex is so well designed that Yugoslav construction firms were reportedly hired by deposed Iraqi dictator Saddam Hussein to build a duplicate bunker near his hometown of Tikrit in the 1980s.

[mgk920]

Secret Complex Exists Underneath Belgrade
Semi-relevant to current events as well:

I remember reading a few years ago about a completely seperate, sort of 'parallel' subway system underneith Moscow that was built for 'official use only' by the Cold War-era Soviet Communists.

Mike