This tall stone wall with no door and ill-matched windows was built centuries ago, and used as a shelter for domesticated pigeons.

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

The mountaintop wind turbine boasts a viewing deck — and a fair share of controversy.

If astronomy had a ghost, it would look like this observatory.

The loneliest island in New York.

A steamer run aground near Bimini lives a second life as a playground for scuba divers.

Storage warehouse of the rich and famous.

A table rock formation that has been intriguing West Virginians for years.

A majestic lion statue guards this Parisian botanical garden, and feeds on an unsettling item.

A picture-perfect town, perfect for blowing up.

Pompeii's less famous neighbor is still revealing her secrets.

A curious whirlpool formation supposedly capable of entangling or engulfing branches, tree trunks, or whole rafts full of hapless tourists.

A stunning, abandoned limestone quarry in southern Indiana provided the stone to erect the Empire State Building.

Massive stele returned to Ethiopia after 70 years in Rome.

Lonely minaret stump of a destroyed city.

A taste of the macabre Tokyo's ritzy shopping district.

A former French military respite turned jungle tourism hotspot.

Fighting the British and making game shows for over 150 years.

Home to the deepest rift anywhere on Earth.

Extremely long cable tunnel buried under the river.

Huge Russian Orthodox cemetery in danger of being converted into open public space.

Manatees congregate around a power plant's discharge canal where the water is especially warm.

Structure built from the skulls of vanquished foes.

Light still pours into the ruins of this ancient Islamic observatory.