Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

A pair of oily black spiders lurk inside South Korea's largest airport.

South Korea's largely symbolic, barely used gateway to the North.

The site of many tense prisoner exchanges across the Military Demarcation Line between North and South Korea.

The best place for scenic views of the DMZ and North Korea.

The world's longest bridge fountain has hundreds of nozzles that create a beautiful, illuminated spectacle.

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

The supreme shrine of the state.

Buy your fish and have it cooked to order in this bustling, eight-floor seafood market.

The name of the only golden Buddhist temple in Korea translates as "the temple that protects the country."

Calcium-rich water has turned the water and rocks of these Philippines falls slightly green.

Along a coast that sees the annual migration of humpback whales, a geological formation that takes the shape of a whale’s tail.

The same water that fills a luxury resort’s pools feeds these free hot springs in the rainforest.

Built on the remains of one the Incas’ most important gathering spots, this square keeps the spirit of a fallen empire alive.

Situated on a sacred Inca site, this 16th-century cathedral took nearly 100 years to build.

Visiting dignitaries and Hollywood stars once stayed at this 1920s hotel, alongside ghosts that are said to haunt its corridors.

If you’ve ever seen a picture of Machu Picchu, then you’ve seen a picture of Huayna Picchu—you just didn’t realize it.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

This volcanic cave lake is essentially hard proof that Iceland is the most magical place on Earth.

Two whaling vessels that were sunk by an anti-whaling organization in 1986 now sit on the shore of this beautiful fjord.

Dozens of large, brightly-colored paintings adorn the walls of the "street art capital of Iceland."

Along this wire fence, travelers have been leaving a particular memento since 2012.

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.