Excelsior Tunnel

In 1959 it was the centre of project Military Atomic Energy Authority operation orpheus investigating the possibility of masking the seismic signal given out by underground nuclear tests.

Vallone dei Mullini

The haunting buildings of the Vallone dei Mullini, or Valley of the Mill, in Sorrento, Italy were only abandoned in the 20th century, according to Atlas Obscura.

Ilha da Queimada Grande (Snake Island)

Snake Island is one of the deadliest and most restricted places on earth. The island lies off the coats of Brazil and is home to at least 4000 species of the world’s most venomous snakes alleged to possess the ability of melting human flesh. The island is banned to tourists and is only open to scientists for study and research.

Sarajevo Tunnel

Five meters below the runway of Sarajevo’s airport runs a short stretch of tunnel that was dug out during the Siege of Sarajevo to bring supplies to the cut-off city. For four years this 800-meter long tunnel was the besieged city’s only connection to the outside world, and its life support.

Željava Air Base

Situated in the west of Bosnia on the border with Croatia, Objekat 505, as it was officially known, was the largest underground airport in the Balkans. The primary purpose of the Objekat 505 was to house a long-range radar early warning system, akin to NORAD, as well as to provide a strategic command center for the country’s defense.

RAF Barnham

In the early l950s, RAF Barnham was selected for development as a dedicated storage and maintenance facility for nuclear weapons, in particular for Blue Danube, Britain’s first nuclear bomb.