The celebrated eyesore created by starry-eyed sweethearts.

19th century pendulum and a clock restored by a rogue group of guerilla artists.

This magnificent castle grew from a small Moorish fortress, and reportedly inspired two iconic Disney castles.

For decades, Puerta del Sol has been illuminated by a giant, guitar-wielding bottle of sherry.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

A winding district gerrymandered into the shape of a mantis.

The haunting "Hell House Altar" is one of the few remnants of an abandoned college that has been a magnet for local legends.

Remnants of a storybook amusement park hidden behind a strip mall.

FDR's Art Deco hospital tower was hopelessly inefficient.

She stares out across six lanes of traffic, clutching a musket and infant with determination.

Washington's top-secret Cold War-era doomsday communications tower is located in a small neighborhood park.

The iconic D.C. restaurant where the Cuban Missile Crisis was negotiated, now a Walgreens.

A derelict bit of transportation infrastructure hidden in the woods.

At 207 feet, one of the world's longest continuous escalators.

The Cadillac Ranch for monster truck aficionados.

This colorful gate stands as an entrance to the walled city of Old San Juan.

An eerie, decaying ghost town destined to fade into the forest.

Captain John Smith thought these cliffs were amazing in 1608 but sharks thought so 20 million years before him.

Surrounded by a verdant garden and a backdrop of ivy, a monument to beloved poet Khalil Gibran stands outside of the Lebanese embassy.

A tribute to the pop culture icon overlooks this Washington D.C. intersection.

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

An ear-piercing buzzer calls lawmakers to a vote with a series of long and short rings to form coded messages.