Ha Long Bay's "Cave of Surprises" houses a popular phallic rock formation.

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

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

A nightmare for the claustrophobic lies hidden in Southeast Asia.

A Surreal flight of architectural fancy in Vietnam's Central Highlands.

The spot where the two men ate together now stands enclosed in glass.

This striking landscape in northern Vietnam contains both geological and archaeological wonders.

This Vietnamese bar doubles as a multistory labyrinth.

An extravagant monument to an extravagantly unpopular Emperor.

Have fun at the world's first Buddhist waterslide park.

This Vietnamese hell cave lets visitors take a walk through a devilish underworld full of demons.

Twice a day a speeding train passes only inches from the homes of this residential neighborhood.

This spectacular bridge supported by two gigantic hands looks like something out of a fantasy universe.

Vietnam's feral abandoned water park offers access to a post-apocalyptic funscape, now with fewer crocodiles.

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

A gateway to a mysterious network of underground tunnels.

A series of waterfalls so massive they straddle the border of Argentina and Brazil.

This stunning mass of ice spans 121 square miles and is still growing.

A mouldering Colombian bull ring stands as a reminder of the country's complicated relationship with a brutal sport.

Ripped apart by a bomb in 1993, the shell of Pablo Escobar's infamous vacation house still stands.

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

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

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

Every Sunday, Bogotá turns 75 miles of its city streets into a bicycle superhighway.