This giant monument of the RCA mascot is a beloved fixture in Albany, New York.

A 10-foot-tall concrete Alley Oop statue left over from World War II now stands on the side of the road.

An interesting look into 18th-century American history.

Craggy concrete faces are hidden in the walls of this artificial cave along the San Antonio River.

Once the center of Gold Rush mania, now the starting point for the Yukon Quest sled dog race.

Ruins from the Parthenon and petrified wood line the interior of one of the world's most famous monuments.

Fantastic views and thousands of love locks.

A 20-foot-tall quarter commemorates George Washington’s ties to Bedford County.

A small etching on the white marble parapet was written in runic script by a Viking mercenary.

Legend says if you stick your thumb in the hole and it gets wet, your wish will be granted.

In the upscale neighborhood of Miraflores in Lima, a pretty little park is home to dozens of cats.

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

These recently uncovered walls are all that's left of Washington, D.C's first defense contractor.

Once a sewer culvert, this road tunnel now offers cyclists and pedestrians a subterranean stroll under the C&O Canal.

A derelict bit of transportation infrastructure hidden in the woods.

This historic boathouse was constructed using salvaged lumber from burned barns.

This stately mansion, built in 1787 by America's first Secretary of the Navy, is rumored to be one of the most haunted buildings in Washington, DC.

Before Metro, Washington had a robust streetcar network—and you see the remains of this infrastructure if you know where to look.

An 18th-century townhouse that once hosted guests of the president.

This site is believed to be connected to the oldest house in Arlington County.

This vast and otherworldly landscape is one of the largest dune complexes in North America.

The remains of a large pueblo village constructed by the Salado culture, who occupied the region more than 600 years ago.

In 2004, a Dave Matthews Band tour bus dumped 800 pounds of waste off a bridge and onto an unsuspecting tour boat below.

These two 15th-century metal rods allowed people to check if they were swindled or not.