A 1,215-foot tunnel transports pedestrians beneath the River Thames.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

A student driver's nightmare.

This contentious squat has stood through fire, violence, and government intervention as a hotbed of leftist protest.

A historic London cemetery now serves as a nature park incorporating gravestones & memorial statues.

A lush green oasis in the middle of Chicago.

This urban drawbridge gained eternal pop culture fame when the Blues Brothers jumped it while it was raised.

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

An avant garde art museum at the University of Chicago.

This abstract sculpture is rumored to cast a hammer-and-sickle shadow once a year.

To find the "unicorns of the deep" you've got to go downstairs.

Where dioramas can follow you home.

Years of archaeology, just chillin' by the water cooler.

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

A display of magnificent stained glass windows is the first exhibit of its kind.

Once at the center of U.S. finance, the historic Trading Room was meticulously recreated piece by piece and rebuilt in the Art Institute.

Each of these gorgeous, intricately decorated rooms is painstakingly crafted to the scale of 1 inch: 1 foot.

Fragments of architectural wonders from around the globe are embedded in the newspaper building's walls.

This historic hotel invented the chocolate brownie.

An eccentric park and pool.

No one knows how many bodies are in this vault in a Chicago public park.

Beloved bar home to musicians of all eras and reputations.

A century-old hotspot for jazz, frequented by everyone from Charlie Chaplin to Al Capone.