Nikola Tesla's ashes are held in a golden sphere, surrounded by his works.

Structure built from the skulls of vanquished foes.

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

The first mosque in the world to receive electricity.

The remains of the last Bosnian fortress to fall to the Ottomans are still standing.

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

A small but hugely whimsical theater where marionettes play out the "The Battle of Stalingrad."

The cave holds a spectacular array of stalactites and stalagmites, including one shaped like a giant human heart.

This neon lit Georgian cave claims to hold the boulder Prometheus was chained to.

Small church on top of a huge rock column.

Fortified homes of highland warriors that are still in use today.

These Stalin-era industrial 'death traps' hang lifeless above the city

This historic timepiece is thought to be the only public clock in the world that keeps lunar time.

The haunting ruins of a military fortress turned astronomical observatory sit on a Sarajevo mountaintop.

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

Inat Kuća, or "House of Spite," is more than just an oddly named restaurant.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

Ship-sized kinetic sculptural fantasy.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

This one has sailed five times as far as Sir Francis Drake's famous ship.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

The first museum in the world devoted to sexual gadgetry.

Macabre astrological automaton clock dating to the late 1400s.

A centuries old castle atop a dormant volcano houses museums devoted to both women and witches.