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

Man-made mineral caves house massive bat colony.

A former imperial sea-fortress and Soviet prison.

Rusted cars, trucks, and buses form a fascinating collection of Soviet-era machinery.

In the foothills of the lesser Caucasus, a centuries-old fortress still stands.

Azerbaijani ghost town, decaying after a war left it an armed forces buffer zone.

This striking icon of the disputed Republic of Artsakh caused a stir at a Eurovision Song Contest.

This memorial park stands on the site of one of the largest mass executions of the Second World War.

Seventy-five miles of limestone caves host more than a million bottles of wine beneath a sleepy Moldovan town.

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

Ancient barriers wrap around what was once an important stop along the Silk Road.

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

This military tunnel dates back to World War II and provides visitors with a little wartime adrenaline.

A self-proclaimed libertarian micro-state on a tiny bit of disputed territory between Serbia and Croatia.

Croatia's towering concrete blossom grows from the site of a World War II concentration camp.

Yugoslavia's biggest underground airport lies in ruins.

This stunning, out-of-the-way Croatian monument commemorates a community's uprising against occupying fascist forces.

Oriental bazaar in the heart of Sarajevo.

This museum preserves the hand-dug tunnel that kept Sarajevo afloat during the Serbian siege.

This top-secret nuclear bunker hidden in a Bosnian mountain has been converted to a modern art exhibition space.

These warring psychedelic crags commemorate an unsuccessful military operation.

A war-torn Olympic relic is being overtaken by graffiti and nature.

An abandoned desert hamlet swallowed up by sand.

This Bangkok high-rise looks like a rudimentary LEGO elephant.