These unusual stone structures are actually fish traps crafted by an ancient civilization.

An abandoned company town and cement factory outside of Bogotá, now haunted by ghosts and scofflaws.

An ancient city hidden in the heart of the Sierra Nevada mountains.

Hidden amid the tropical forest in the Caribbean Sea are the decaying ruins of the Cocaine King's luxurious island party home.

In the middle of one of South America's most historic walled cities lies a bar with an enormous collection of Soviet memorabilia.

A cozy bookstore and coffee shop in the heart of Cartagena's Old City.

Perched atop the highest hill in Cartagena, this 17th-century convent offers spectacular views of the city.

A 400-year-old mummified arm dangles from the ceiling of St. James the Greater, serving as a warning to thieves.

This massive library holds what was once the largest book collection in the world.

These ornate manhole covers were used for a now-forgotten purpose.

New York City's smallest piece of private property.

This museum’s collection includes rescued birds, fine art, and a collection of shrunken heads.

Building this tragically pointless stone barrier cost the lives of the prisoners made to build it.

Since the 1700s, this old barrel has acted as a post box that relies on the kindness of travelers.

In this pristine Ecuadorian hippie town, residents remain active well into their eighties and nineties.

This small uninhabited island offers Galapagos-like biodiversity.

This cave system allegedly holds the "metallic library" of a lost ancient civilization.

These mammoth-yet-narrow crevasses in the Earth are perfect for taking an otherworldly swim.

Ecuador's largest Incan ruins show evidence of sophisticated irrigation and diplomacy among the ancient builders.

This slender three-story building has also had several famous residents.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

Visit the site of a subway powered by nothing more than air--and lots of it.

Try not to get slimed in Tribeca.

Built hundreds of years ago this downtown iron barrier once protected a much despised king.