This once-popular otherworldly landscape was formed by one of the largest volcanic eruptions in history.

This 13th century Gothic brick castle is the largest in the world by surface area.

This fairytale medieval church in Poland originally spent centuries in Norway.

Countless stories attempt to explain Poland's mysterious J-shaped trees.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

Collapsing castle on the Hudson river was once the storage site of military surplus business.

100 massive sculptures in the Hudson River Valley.

A sculpture outside London's oldest cathedral honors the Mohegan chief who died while petitioning the king.

After nearly 60 years, there's still a bear at Paddington Station looking for help.

This hidden green space is the city's second largest conservatory.

World Trade Center memorial likened to a woman's sexual organ.

The highest point in New Jersey is marked by a massive, if simply named, obelisk.

These mystical miniature houses bring a touch of magic to the New Jersey woods.

The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

Wine bottle sculpture with a ship's stateroom inside.

Rat sculptures try to infiltrate the Graybar Building in an architectural tribute to New York City's nautical history.

A sculptural commentary on capitalism pokes up from the East River.

Plot your trip through the city on the sidewalk.

A student driver's nightmare.

Little Red Lighthouse under the George Washington Bridge.

This futuristic airport terminal was abandoned for decades before reopening as a hotel—with a vintage plane of its own parked out back.

Lie in a hammock where George Washington stood.

Ride the subways of yesteryear.

One of only two commuter aerial tramways in the United States.