This beautiful system of tunnels built into natural rock serves as a centuries old plumbing system.

Ancient structures used to make and preserve ice in the deserts of Persia.

A 1,500-year-old, 3-story subterranean city where ancient Persians took refuge in times of war.

Putrefaction plateaus in Iran, where the dead were sent for decontamination before going to their final resting place.

A spectacular rainbow of stained glass makes the "Pink Mosque" one of the most beautiful in Iran.

The palace of the King of Kings, burned by Alexander the Great.

Iran's colorful terraces are a rare geological masterpiece.

Mirrors and glass shards cover every inch of this arrestingly beautiful mosque.

One of the world's tallest Ferris wheels takes visitors high above Las Vegas in a spinning party room.

Stepping away from the glitz of mobsters and casinos to learn about the other history of Vegas.

Thousands of artifacts relating to human sexuality, including the world's largest sex bike.

A nightmare for the claustrophobic lies hidden in Southeast Asia.

This collection of reclaimed landmines acts as both an exhibition of their deadly history and as a shelter for children affected by them.

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

A small subculture of boat dwellers keep their traditional way of living alive at this Hong Kong Typhoon Shelter.

This naval gun is fired every day at noon, an odd timekeeping tradition the origin of which is local legend.

A serene space tucked amid the skyscrapers of Hong Kong's bustling financial district.

Thousands of abandoned statues of deities are taken to this hillside in southern Hong Kong.

A pair of trees near a Hong Kong shrine are said to grant wishes, but only the ones they hold on to.

Take a cruise with no movement but plenty of style in this one-of-a-kind boat mall.

If you've ever wanted to tear Hello Kitty apart with your teeth, this is the place.

Remnants of the most densely packed city in world history, that thrived on anarchy for 30 years.

A colossal floating restaurant built to look like a ancient Chinese imperial palace.

Built by King Norodom to honor his late father.