A hidden treasure of an abandoned city lies deep in the jungles of Campeche, Mexico.

A natural swimming hole that was once a ceremonial center for Mayan priests.

A massive underwater sinkhole made famous by Jacques Cousteau.

Cave where bat-eating snakes hang down from the ceiling.

An important Mayan religious and trading center dating back to 200 BC.

This portion of a lovely Belize beach is infested with (harmless) sharks and rays.

A bright, colorful telling of the history of Mexico's youngest state.

When waves crash onto this section of beach, the rocks sing a song.

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

Breathtaking and huge 430 year old maps of Italy.

The last remnants of what was once one of the world's grandest hotels can now be found in a Manhattan subway station.

More gold than anywhere else, ever.

Meant to be a lavish presidential home, the palace became a symbol of the fall of South Vietnam.

This French colonial post office is arguably the grandest in all of Southeast Asia.

Artifacts and memories from the Vietnam war, located in a place that experienced it first hand.

This Vietnamese bar doubles as a multistory labyrinth.

These crumbling towers are some of the last remnants of a centuries-old Vietnamese culture.

Monument to a brutal, ineffectual US bombing campaign and a sobering reminder of the human cost of the Vietnam War.

An extravagant monument to an extravagantly unpopular Emperor.

When Azorean green tea meets volcanic hot springs water, a luminous brew is born.

World's largest cave was only discovered in 1991, and now offers tours to the public.

At a Bangkok bistro, one pot of beef stew has been cooking non-stop for more than 45 years.

The largest madrasa in Morocco once housed more than 900 students within its exquisite walls.

The ornate miniature mansions were built for Istanbul's feathered residents.