Secret North Korean passage discovered below the world's most dangerous border.

Home to more than 13,000 pieces of war memorabilia and military equipment.

Tracking the 1,500-year history of Korea's star cabbage.

A chilling monument to Korean patriots who resisted the Japanese occupation.

All that remains of this abandoned coal town is a beautiful, haunting cemetery.

This volcano rises like a giant anthill from the plains below, with a road spiraling up to the rim.

Some 2,000 carvings show this rare desert spring has been an oasis for travelers for over a thousand years.

The ruins of this abandoned fort now stand as a picturesque reminder of America's march West.

A small metropolis of Pueblo cave dwellings have been carved right into the hillside of this national monument.

Despite time, colonization, and the brutal New Mexican heat, these Pueblo ruins still stand.

A phenomenal assembly of pueblos in New Mexico is the most complete example of ancient ruins north of the border.

These aggressively sustainable art homes look like something out of 1970's science fiction.

The grave of America's 11th president is not in some grand monument but instead it's hidden away on the grounds of the Tennessee Capital.

The mastermind behind this palatial hotel perished on the Titanic weeks before its grand opening.

Louise Bourgeois' 30-foot-tall steel spider sculpture.

This midcentury chapel is a bold architectural statement and a symbol of Indiana's Lutheran heritage.

The oldest continuously occupied public building in the United States.

This southwest-styled home in Santa Fe claims to be the oldest house in America thanks to an ancient bit of foundation.

Wedding chapel's mysterious spiral staircase said to be miraculously constructed.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

A naturally mummified 2,000-year-old man.

The television series' iconic giant foot was borrowed from this classical painting.

Hear the quietest sound from across the dome.