Once decrepit and slated for demolition, now one of the longest pedestrian bridges in the world.

This historic oak tree has been around for over 300 years and might last for 300 more so long as it doesn't fall apart first.

One of the largest-ever mental hospitals now sits abandoned, surrounded by 25,000 unmarked graves.

The yawning maw of this pagan visage is said to bite off the hands of liars.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

The only arched bridge made of stone on the entire Mississippi River.

A beautiful geyser under environmental threat.

Illegal drag racing two stories beneath Chicago’s streets.

This "second" cemetery represents New Orleans' attempt to keep cholera at bay.

This Wall Street bar was once a hub of revolutionary activity where Washington famously bid farewell to his troops.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

This historic "City of the Dead" lies prominently in the center of New Orleans' famous Garden District.

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

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

Elevated freight railway turned wildly successful urban park.

Downtown Minneapolis mixed art and function by turning some of their sewer covers into works of art.

At this Minnesota state park you can easily wade across the source of the mighty Mississippi.

A haunting army of decomposing, moss-covered stuffed animals and dolls guard this swinging truss.

A restaurant and lodge in northern Wisconsin which served as a clandestine hideout for John Dillinger and featured one of the most famous botched FBI raids in history.

An abandoned bus station transformed into a museum dedicated to the history of Greyhound Lines, in the place where it all began.

The watery grave of an impractical idea.

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

The palatial McDonald's that inspired Wesley Willis.

The world’s largest truck stop includes a barber shop, chiropractor, and a huge museum with antique trucks.