one

The Wolf’s Lair

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

Gulliver’s Travels Park

The park was built next to Mount Fuji near Aokigahara - Japan’s famous ‘suicide forest’ - and close to the former headquarters of Aum Shinrikyo, the religious cult responsible for 13 deaths in the Tokyo sarin nerve gas attack of 1995.

Mirny Diamond Mine

The Mir mine, also called the Mirny mine, is an open pit diamond mine located in Mirny, Sakha Republic, in the Siberian region of eastern Russia. The mine is >525 meters (1,722 ft) deep (4th in the world) and has a diameter of 1,200 m (3,900 ft), and is one of the largest excavated holes in the world.

Borovsko Bridge

The Borovsko Bridge is an unfinished highway bridge near Borovsko , part of Bernartice municipality, Central Bohemian Region, Czech Republic. It is commonly known as the "Czech Avignon" or "Hitler's Bridge".

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.

Juragua Nuclear Power Plant

Juragua Nuclear Power Plant was a nuclear power plant under construction in Cuba when a suspension of construction was announced in 1992 following the collapse of the Soviet Union and the termination of Soviet economic aid to Cuba.

Barbados HARP Gun

The Barbados HARP Gun, was part of Project HARP, short for High Altitude Research Project, which was a joint project of the United States Department of Defense and Canada's Department of National Defence created with the goal of studying ballistics of re-entry vehicles at low cost; whereas most such projects used expensive and failure-prone rockets, HARP used a non-rocket spacelaunch method based on a very large gun to fire the models to high altitudes and speeds.

Prora

Prora, also known as the Colossus of Prora, is an enormous building complex on the island of Rügen, Germany, that was built by Nazi Germany between 1936 and 1939 as a beach resort of the Strength Through Joy (Kraft durch Freude or KdF) project.

Presidio Modelo

Presidio Modelo (Model Prison) was a former “model prison” of Panopticon design, located on the Isla de la Juventud in Cuba, built between 1926 and 1931, during the repressive regime of Gerardo Machado.

Vajont Dam

The Vajont Dam (or Vaiont Dam) is a disused dam in Italy, which was completed in 1959. On 9 October 1963, during initial filling, a massive landslide caused a man-made megatsunami in the lake in which 50 million cubic metres of water overtopped the dam in a wave 250 metres (820 ft) high, leading to 1,910 deaths and the complete destruction of several villages and towns.

Erta Ale

Erta Ale (or Ertale or Irta'ale) is a continuously active basaltic shield volcano in the Afar Region of northeastern Ethiopia. It is situated in the Afar Depression, a badland desert area. Erta Ale is the most active volcano in Ethiopia.

The Black Hills Ordnance Depot

The complex contains over five hundred nuclear-hardened concrete military bunkers, partially buried underground and protected by thick berms of earth, to resist a surface blast wave, as well as radioactive fallout.

ATLAS-I

ATLAS-I is world’s largest wood and glue structure designed to test the radiation hardening of strategic aircraft systems against EMP pulses from nuclear warfare.

Barbarastollen Underground Archive

Germany’s “treasure chamber” is located in a disused mine near Freiburg. Documents from over a thousand years of history are stored in the underground archive.

Bagger 288

Bagger 288 (Excavator 288), built by the German company Krupp for the energy and mining firm Rheinbraun, is a bucket-wheel excavator or mobile strip mining machine.

Stelling van Amsterdam

The Stelling van Amsterdam was the most advanced military structure of its type in the world - 135 km (84 miles) of forts, batteries and moats completely encircling the city in a defensive barrier.