Metro station with a claim to rock n' roll fame.

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

Berlin's old airport.

A restaurant and observation deck built in a unique broadcasting antenna.

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

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

A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

In one Chicago park, a trio of werewolves are waiting to devour their fallen brethren.

Chicago's Navy Pier on Lake Michigan was a training hub for aircraft carrier pilots during WWII.

These chunky stone towers out in Lake Michigan are the key to Chicago’s drinking water.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

A little-known subterranean street runs under some of the best-known buildings in Chicago's River North.

This $3 million model train takes you through Chicago, Seattle, and the thousands of miles in between.

The twin towers in this Chicago fountain use 50 foot tall video screens to spit on people.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

Mosaics, storks, and brothels—this ancient city has it all.

Traditional 11th-century outdoor tannery.

The courtyard of this small Marinid madrasa is a dazzling example of intricate Islamic architecture.

Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

An eerie former warehouse turned cistern turned movie set.

An awe-inspiring mosque in Morocco with one of the tallest minarets in the world.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

The medieval castle built as headquarters for the Pope's secretive Knights Templar.

Remarkably intact Roman stone fortifications have encircled this Spanish city for centuries.