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

This attraction was abandoned after the Chernobyl disaster.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

A cathedral resurrected from the ashes of one of Europe's greatest urban fires.

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

Architecturally stunning library serves as the hub of Finnish scholarly life and culture.

The oldest museum in Russia is home to a fascinating collection of nearly two million anthropological artifacts and anatomical curiosities.

Nightmarish example of the unintended consequences of weapons testing.

A man-made island fort that has housed soldiers, scientists, and ravers.

An 18th century wonder of the world, lost in WWII, re-created at the Catherine Palace.

An empty relic of the Moscow Olympics crumbles away in Estonia's capital.

A decommissioned submarine base makes a great space for graffiti art.

Mysterious craters may have been home to an ancient cult.

Launch site for nuclear war against Western Europe.

Spend the night in 1920s Latvia in this historic recreation and movie set.

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

Museum deep in the catacombs of St. Michael the Archangel Church is explored by touch, sound, and smell.

First point in the Struve Geodetic Arc, a 19th century undertaking to measure the Earth's size and shape.

3,000 market stands in five former Zeppelin hangars.

Flamboyant architecture from the turn of 20th century.

Menacing or in memoriam, the Silent People and their meaning are left to interpretation.

World's strongest whirlpool.

The world's northernmost aquarium looks like it has fallen over.

A series of modernist treehouse hotel rooms grace the outskirts of an Arctic forest.