This shop for all your super spy needs hides an educational secret.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

The highest point in Tennessee, Clingmans Dome bears witness to the ravages of one type of insect.

The glowing blue Nymphaeum of Emperor Tiberius.

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

Huge abstract sculptures of the Puerto Rican Flag.

The original Garfield station is the oldest station facility on the "L", with the station house dating from 1892.

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

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

The beloved home to all publications indie, erotic, and punky.

Illegal drag racing two stories beneath Chicago’s streets.

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

In a quiet north Chicago neighborhood rests a stunning relic of the golden age of earthenware design.

Not to be confused with the iconic New York City skyscraper, this Chicago building is a vibrant hub for artists.

This memorial plaque remembers a strangely shallow maritime disaster known as "Chicago's Titanic."

This cheerfully-named branch of the Chicago River is the fetid result of years of blood, entrails, and meatpacking waste.

This bronze sculpture on a former squash court marks the secret origins of the Atomic Age.

Once called the "Polish Gold Coast" it is an icon of the neighborhood that bears its same name.

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

These mansions date back to Chicago's days as a brewer's paradise.

Half-sized replica of the Leaning Tower of Pisa built to honor Galileo.

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

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