An abandoned Incan construction project left behind a mysterious "doorway."

After an epic flood washed away its enslavers, this city has been part ghost town, part cultural wildcard for the past three centuries.

An abandoned Ecuadorian prison that once held ex-presidents and notorious con artists is now a carceral museum.

The remains of an ancient settlement in one of the oldest archeological sites in South America.

This research hub in the Amazon Rainforest is perched amid one of the world's most biologically diverse landscapes.

A turquoise lake within a volcanic crater.

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

A swing to dangle you off the very edge.

An Ecuadorian haberdashery that sets the record straight about the so-called "Panama" hat.

The Incas turned this ancient Wari aqueduct into an imposing defensive gate.

Did Inca children also slide down these smooth rocky slopes above Cusco?

Death rituals and sacrifice inside a Peruvian megalith.

This Peruvian canyon is filled with geometric salt pools that have been being harvested since the Incan empire.

Huge stone depressions which may have acted as an Incan agricultural experiment.

The stones of this Incan wall complex fit together so well you couldn't fit a piece of paper between some of them.

Preserved Inca city and site of the last Inca stronghold against the Spanish conquistadors.

A remote candy-striped mountain in the Peruvian Andes straight out of the pages of Dr. Seuss.

Keshwa chaca, among the last handwoven Incan bridges, crosses Apurimac Canyon in Peru.

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