A small isolated country littered with strange concrete mushrooms and a secret Japanese facility that was once at the forefront of weapons technology.

What happened to an infamous pirate city in Jamaica? Also, a grim gulag in Croatia and a Louisiana plantation caught up in the aftermath of the American Civil War.

Examining a ghost island once belonging to a secretive country on the fringes of Europe. Also, a haunting site in the UK with evidence of strange burial practices.

Within a dense Polish woodland sits a forgotten complex with an explosive history. Also, grand coastal defences in Ghana reveal a tortured past.

A complex of stone buildings near Hadrian's Wall that were built to keep Northern hoards at bay. Also, a top secret military facility in the American Midwest.

An extended special featuring a deserted Caribbean city, an American ghost town still burning and an Arctic settlement facing a terrifying future.

A now silent site that played a pivotal role defending the U.S through the 20th century. Plus, a crumbling Italian fortress and a ghostly Ukrainian mansion.

A juggernaut of Soviet engineering which was crucial to the international space race. Deserted Scottish coastal defences and a complex that's crucial to American history.

The mysterious Cachtice Castle home to Elizabeth Bathory, said to have killed over 600 girls and a mysterious structure on the 38th parallel.

A creepy collection of buildings, monuments hidden in a Parisian park and an eerie graveyard of discarded ships strewn along the banks of a mighty river.

An impressive compound commandeered and repurposed by a brutal regime and an eerie complex off the coast of Ireland that became the biggest of its kind.