

Exploring Air Studios, on the Island of Montserrat, that became a mecca for rock legends. Also Tskaltubo, in Georgia, built to host a fearsome dictator.

Exploring Haludovo Palace Hotel in Croatia, Wolf's Lair, a German military complex and Herouni Mirror Radio Telescope - a pioneering facility in Armenia.

Exploring a theme park in Buenos Aires built in a time of terror and dogged by controversy, and a jaw-dropping collection of castles in Turkey.

Exploring Dover Commando Fortress in South East England, where traces of a top-secret Commando raid are still visible.

Exploring Old Byron Hot Springs in the Californian desert - a once glittering Hollywood hotspot, converted into a top-secret interrogation centre.

A symbol of national pride that became a symbol of excess in the Turkish capital of Ankara.