Graffiti from the 16th and 17th centuries cover the walls of this part of the Tower of London.

The Cadillac Ranch for monster truck aficionados.

Frank Lloyd Wright built this suburban synagogue late in life, but it stands among his most iconic masterpieces.

These unusual rooms on wheels are holdovers from the 1960s.

The story behind the mysterious symbol painted in front of the historic university's famous Rotunda.

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

This psychedelic tromp l'oeil seems to be beckoning drivers to crash into a wall.

A Norwegian-born sculptor created these soaring guardian angels at the entrance to Hoover Dam.

Experience a charming 1930s version of "infotainment."

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.

There’s a hidden military meme engraved on the World War II Memorial.

This picturesque horseshoe weir was first built in the 1600s to prevent flooding in the town of Bath.

A blend of art, antiquities, and Americana fill this museum, surrounded by whimsical, enchanting gardens.

A sinister pyramid in the Frari contains the heart of the famous neoclassical sculptor.

This weeping, 10-foot-tall sculpture was a maquette for a 9/11 memorial.

This local gem houses the largest collection of pre-Raphaelite paintings outside of the U.K.

This Roman statue is missing a limb from when the Venetians stole it from Constantinople during the Crusades.

This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.

Affectionately known as "Lord Bot," this historic statue has a cult social media following and rightly claims to be “the most metal inhabitant of the Wren Yard.”

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

An overlooked memorial honoring the local Washington residents who died in World War I.

The original toys that inspired the beloved children's stories are on display at the New York Public Library.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.