A marvel of Byzantine engineering under the streets of Istanbul.

This remote British Imperial telegraph relay outpost drove men insane.

Shipwrecks, ruins, and turtles are all that remain on this haunting Caribbean ghost island.

An old slave lookout in Cuba's historic sugar cane fields.

This imposing memorial contains the remains of Che Guevara — and 29 other guerrillas who died with him in Bolivia.

After the Cuban Revolution, the famous rum company had to leave their swanky headquarters behind.

A focal point of the Cuban government, this city square features one of the most iconic images in the country.

These Egyptian statues have survived for 3,400 years and were an acoustic wonder of the ancient world.

Breathtaking and huge 430 year old maps of Italy.

A beautiful Greco-Roman structure houses a well once believed to have healing powers.

Largest lake in Great Britain measured by surface area.

Islanders once used this dramatic, otherworldly landscape to hide their cattle from Viking raiders.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.

An ancient Scottish rock formation said to be the gravesite of a giant remains ensconced in legend and intrigue.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Ship-sized kinetic sculptural fantasy.

A community of artists and entrepreneurs seeks a simpler life on London's waterways.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

One part local history, 99 parts gruesome haunted house.

The bears of Bern have been a city highlight for over 500 years.

A nearly 500-year-old sculpture depicts a man eating a sack of babies, and no one is sure why.

Legend has it that this large rock maze in Sweden was created as punishment by the daughter of a wealthy captain.

A Gothic-inspired fish market is Gothenburg's best place to find loaves and fishes.