Lebanese castle built by one man, over a lifetime.

Commercial airplanes land mere feet over the heads of sunbathing beachgoers on this tiny island.

Two geological phenomena in one precarious locale: a towering stone window, and a deep blue void.

The charmingly disheveled clock tower of Tbilisi's puppet theater.

Luxury hotel turned into a refugee camp, then turned back into a luxury hotel.

A massive, heart-shaped, wind-carved crater in the middle of the Israeli desert.

An ancient capital city that dates back 3,000 years old and harbors many surprises.

Gladiators battle and chariots race daily in the ruins of a once-great Roman city.

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

A mysterious dark-skinned Christ statue has been this town's religious center for centuries.

Cathedral carved out of salt, located a mile below the earth's surface.

Every equinox this Maya pyramid puts on a spooky ancient light show.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

340-foot statue built to honour the Heroes of the Soviet Union.

An underground city of salt.

A 17th-century mosque that was used for war more than worship.

In the land of the Light Brigade stands a testament to the Cold War.

Bridge that died in war and was resurected.

The central mosque of this Mali town is entirely built from mud.

Massive stele returned to Ethiopia after 70 years in Rome.

An Ethiopian "Jerusalem" featuring a church hewn out of a single rock.

This small group of sand dunes manages to pack in a strange rainbow of colors.