This series of Scottish caves has no clear purpose other than baffling historians.

The world's first underground farm is in a World War II bomb shelter beneath the streets of London.

A historic house left in "dramatic still life."

One of the oldest scientific gardens in Britain, containing more than 13,302 plant species in its core collection.

Surreal riveted sea forts once protected the Kent shores from German attack.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

A subterranean ice warehouse that has lain hidden beneath central London for over a century is now open to the public.

These brass bunnies honor the rabbits that dominated the no-man's-land around the Berlin Wall.

This wooden recreation of a 9th century lake village looks as though it was built yesterday (which it relatively was).

An old hill fort covered in over 100,000 crosses is a symbol of Lithuanian nationalism and beliefs.

A top secret Cold War bunker hidden beneath a Latvian spa facility is now open for tours.

Medical museum that houses most notably the taxidermied remains of Vladimir Demikhov's famous two-headed dog experiment.

3,000 market stands in five former Zeppelin hangars.

Flamboyant architecture from the turn of 20th century.

A former Latvian headquarters of the brutal KGB secret police is now open as a grim reminder of their atrocities.

A symbolic graveyard for the villages that perished during the Nazi invasion of Belarus.

Remains of the old fortification along the Western border of the USSR, now an elaborate defense museum.

Glowing orb in Minsk houses 8,600,000 items.

Thanks to its heroic service during WWII this Soviet castle has been turned into a monument towered over by a brutalist titan.

A small museum in this border city displays the contraband art that has been stolen back from smugglers.

Welcome to the world's only museum dedicated to the Ukranian Easter egg.

This attraction was abandoned after the Chernobyl disaster.

This derelict superstructure was a very important warning system for the Soviet military.

Sculpture that doubles as a time capsule so that life can survive radiation outside Chernobyl.