But who was it that built these mysterious structures? What incredible stories surround them? What secrets do they hold? And why were they abandoned? Once these extraordinary places and objects were at the cutting edge of design and construction, but now they stand disused, sometimes contaminated and sometimes dangerous. Britain's Sea Fort ComplexĪ strange group of rusting structures off the coast of England, a dilapidated mediaeval-style castle in the heart of urban America and one of the biggest machines ever built lying forgotten in a German field.

Other structures examined in the first episode include the incredible vertical Phoenix Shot Tower in Baltimore, which was built to provide America's own ammunition, the former American spy instillation called Teufelsberg (or 'Devil's Mountain') in Berlin which waged the Cold War against the Soviet Union, and the now derelict Rubjerg Knude Lighthouse which was built on Europe's second-fastest moving sand dune in Denmark. In 1945 an Allied air raid pulverised the plant, severely wounding the German war machine and leaving the site in ruins. It used the latest technology at the time, at great expense, to turn coal into oil. The site was built in 1937 as part of Nazi Germany's drive to become self-sufficient on fuel, but it was no ordinary refinery. A dark past explains why the Pölitz Synthetic Fuel Plant in Northern Poland is now a derelict industrial site littered with tunnels, bunkers and huge crumbling concrete structures lost in dense forest.

Quest for infamy tunnels