An underground city of salt.

The largest collection of death masks in Ukraine.

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

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

Sulphuric gases inhabit a beautiful Japanese island.

This ruined Japanese stripclub sits half burnt to the ground.

A beautiful, dense forest in the shadow of Mount Fuji, with a tragic reputation.

The world's largest drain sits below the city of Kasukabe, Japan.

A taste of the macabre Tokyo's ritzy shopping district.

One of the most horrible legacies of the Cold War is a site where the Soviet Union tested nuclear bombs on civilians.

Once the most densely populated place in the world, this island is now a ghost town.

Once a bustling fishing port, this semi-ghost town is now more than 90 miles away from the shore.

Former island in the Aral Sea used to be a top-secret Russian bio-weapons facility.

World's oldest and largest space launch facility, once a secret missile testing site.

Rusting ships sit in a desert where a sea used to be.

Bridge that died in war and was resurected.

Extensive private collection of authentic Medieval devices used for human torture and execution.

Yugoslavia's biggest underground airport lies in ruins.