An avant garde art museum at the University of Chicago.

These pretty kitties killed and ate as many as 135 railway workers.

A hot dog stand where the heads are just as hot as the dogs.

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.

Hot Doug's "Hot Dog" Stand.

A teddy bear sits on a chair watching the sunset from the mountaintop—just as the late Dan Clancy had done since childhood.

In the 19th century, this canal provided power to mills, machine shops, and other businesses in the area.

This 150-year-old train station and caboose have been turned into a railroad museum, enjoyed by young and old alike.

World War II bunker still standing on the New Jersey beach.

This softly rounded mansion was built without corners not to avoid evil spirits, but to make them more comfortable.

Where Venice's gondolas go for a tune-up.

This abandoned island off the Venetian coast has been a radical monastery, a political prison, and a secret Nazi base.

A melancholy jester sits on the grave of a famous 20th-century ballet dancer and choreographer.

An island on the Venetian Lagoon hosts this stone chair that has nothing to do with the King of the Huns.

In the past, Renaissance sex workers were encouraged to entice customers on this bridge.

The world's oldest optical museum is an odd collection where the exhibits look at you.

The Tudor-style cottage in the middle of the square is not quite what it seems.

Museum dedicated to the UK's first charity for abandoned children, with keepsakes of the mothers who left them behind.

The first tunnel to be dug beneath a river, repurposed as an art and museum space.

The plague quarantine island home to the alleged "Vampire of Venice."

Go inside to really appreciate this 500-year-old technological masterpiece.

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

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.