These caves secretly held national treasures during World War II.

An often overlooked ancient site in downtown Athens with substantial history (and nature).

One of the greatest collections of coins in the world is housed in the former mansion of an archeological pioneer.

The ruined doorway is a portal to the building's turbulent and torturous past.

The ruins of an ancient Roman tomb hidden in the basement of a trendy clothing store.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

A frozen oasis lies beneath the scorching New Mexico desert.

Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

Get lost in this haunting fairytale art walk through a man-made eucalyptus grove.

A small section of Boise, Idaho maintains the unique culture and traditions of the Basque people.

When in Idaho, sleep in a giant potato.

Jail from the 19th century that was built by inmates.

A legal loophole makes it possible to get away with murder within this 50-square-mile section of Yellowstone.

Despite his legacy of work in Spain, Cuba, and Florida, the larger-than-life writer's grave is a simple affair tucked in an Idaho cemetery.

Natural rock water slides hidden in the remote forests of northern Idaho.

This shallow pit was once used to send over 20,000 buffalo plummeting to their death.

A beautiful geyser under environmental threat.

The first declared National Monument in the United States.

Templar knights fleeing persecution are said to have left this sword in stone as a landmark in 1307.

This lake was sacred to the Sabine people who constructed a temple here on a floating island.

This medieval settlement was abandoned after a series of landslides. What remained was largely destroyed during a mock battle for a WWII film reel.

A taste of Middle Earth, in the middle of the Bayou City.

Run by members of the Tohono O'odham Nation, this community farm nurtures traditional desert cultivars.