The ornate miniature mansions were built for Istanbul's feathered residents.

A 12th-century fortress containing some of Berlin's oldest buildings.

Home to 10,000 medical specimens including the remains of Rudolf Virchow's extensive collection of pathological specimens.

This World War II bunker now survives as a documentation of the Nazi regime and war crimes.

A collection of abandoned typographic signs from Berlin and beyond.

This Roman monument is surrounded by more recent construction, offering a stark contrast between ancient architecture and the modern urban landscape.

This spire on an Austrian mountain is wrapped around a long spiral slide and has the world's tallest wooden observation deck.

When this monument to Slovenia's national poet was erected, it's said to have sparked the ire of nearby church authorities.

Thousands of medieval skeletons lie just beneath Kranj’s main square.

This lush, scenic spot was carved by the turquoise waters of the Radovna.

Workers have collected salt here in a process virtually unchanged since the Middle Ages.

Seek out ‘The Devil’s Court’ in this concert venue located in a former monastery run by an order of Teutonic knights.

Inspired by the Rialto Bridge in Venice, these three clustered bridges were just one part of a Slovenian architect’s grand vision.

First founded in 1472, this is the oldest bank in the world. Its history may explain why we call financial institutions "banks."

A dismembered holy head stares out from her beautiful reliquary at the St. Dominic Basilica.

These medieval skyscrapers dominate the skyline of this small Tuscan town.

The mysterious “claw marks” said to be left by the Devil on Pisa’s famous cathedral.

Next to the Leaning Tower of Pisa is a cemetery home to ancient sarcophagi and disturbing murals.

Fortified medieval tower house with lovely roof garden.

This bustling Italian plaza is built on the ruins of an ancient Roman amphitheater.

The naturally mummified body of a peasant girl saint.

This Slovenian museum houses the country's largest collection of painted beehive panels.

Huge stairway leads to this massive gallery.

A plaque on the base of this statue holds a bewitching design.