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

A number of craters left by fatal mortar strikes have been filled with red resin to remember those lost during the Siege of Sarajevo.

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

In the hinterlands of Serbia's capital, a giant reflective mushroom houses an aeronautical history of the former Yugoslav republic.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

A pair of connected skyscrapers form this symbolic gateway.

The unusual sculptures are believed to be powerful political symbols.

A misnamed well, with a deep dark past.

Destroyed Serbian army headquarters sits half crumbled in a largely revitalized Belgrade.

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

A cluster of historic bathhouses built on the famed hot springs that gave the Georgian capital its name.

An imperial fortress city that incorporated cultural elements from the entire Mughal empire, only to be abandoned the year it was finished.

Hundreds of Buddhas in a re-discovered Indonesian temple.

Subterranean place of worship in Indonesia.

Cold war icon and onetime "hole" in the iron curtain.

The walls of Germany's Parliament still show the scars of the Red Army takeover in World War II.

Berlin's old airport.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

An eerie, derelict amusement park in Berlin.

This Transylvanian church has changed its denomination four times.

One of the most controversial statues in Romania is an emperor with no clothes.

A fire once nearly devoured this gorgeous 14th-century Gothic cathedral.