Built as a gift to the hottest tastemaker of the time, these hidden quarters remain an Art Deco showpiece.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

The name of this famed hospital was once a byword for the horrors of medical and psychiatric care.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

One of only two commuter aerial tramways in the United States.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

The palatial McDonald's that inspired Wesley Willis.

Illegal drag racing two stories beneath Chicago’s streets.

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

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

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

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

A speakeasy takes on Chicago's drinking culture.

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

This whimsical Oz-themed park had a wonderful impact on the surrounding neighborhood.

Home to the world's largest refracting telescope and the birthplace of modern astrophysics.

Quirky water tower advertises the long-gone Brooks Tomato Products Co.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

Real bones which are said to have belonged to a Polish dragon.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

An underground city of salt.

Explore this medieval cathedral by trying to spot all the malevolent monsters hiding in its beautifully colored windows.

There has been an astronomical clock on this spot since the 14th century.