An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

The castle was reconstructed to fit Kaiser Wilhelm II's romanticized vision of the Middle Ages.

A copy of the Statue of Liberty greets visitors to the birthplace of Auguste Bartholdi.

Bordered by forest on three sides and the ocean on the other, the Great Dune of Pilat is the highest sand dune in Europe.

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

This modern French ossuary contains the jumbled bones of 130,000 WWI soldiers.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Macabre astrological automaton clock dating to the late 1400s.

Castro's communist ice cream mothership has been serving five-scoop "salads" for over 50 years.

Neo-cave art on the macro scale.

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

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

In terms of history and architecture, this is one of the most remarkable cemeteries in the world.

The stoutest tree in the world.

This church, buried halfway in lava rock, is all that remains of a Mexican village destroyed by a volcano.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

An Aztec temple, the largest man-made pyramid in the world, sits buried in earth with a Spanish church set on top.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Every equinox this Maya pyramid puts on a spooky ancient light show.

The royal seat of Henri Christophe, a formerly enslaved man who became Haiti's only king.

This iconic fortress was once the crown jewel of Haiti's national defense.

After Christopher Columbus died, his son built a fancy house to rule from.

The oldest colonial fortress in the Americas was once the home and later prison of Christopher Columbus.

Built in 1512, the oldest cathedral in the Americas.