Storied crypts fill the most famous cemetery in Colombia.

The fully functional, submerged Vanuatu Post Office is definitely one of a kind.

A huge, bustling local market in Panama City.

The rusting hulk of a hand-powered, nearly 160-year-old submarine abandoned in 1869 due to the ravages of decompression sickness.

The remnants of an archaeological camp stand within Tikal National Park.

Central America's deepest lake is actually a volcanic caldera, surrounded by three volcanoes.

Hidden deep in the Guatemalan jungle is a turquoise paradise of natural pools, caves, and waterfalls.

A small etching on the white marble parapet was written in runic script by a Viking mercenary.

The ancient latrines of the Greeks, in all their public glory.

Over the centuries, this island paradise has done it all, from providing monks with ecclesiastical respite to sheltering an exiled Leon Trotsky.

Roman ruins, natural methane fires and a lovely beach.

A meow-velous tribute to a beloved street cat, made famous on the internet.

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

A deadly ancient portal to the underworld.

This famous city eluded concrete detection until the early 2000's.

Roman ruins top white travertine terraces formed by ancient hot springs.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

A fountain standing as a testament to a doomed alliance.

Large miniature theme park with 100-plus models.

1513 Turkish world map, full of European state secrets and snarky commentary.

Step back in time and witness the fall of Constantinople.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

A marvel of Byzantine engineering under the streets of Istanbul.

Home to the unidentified remains of the 1979 Mt. Erebus Disaster.