This exceptionally well-preserved ancient marvel also houses a small museum dedicated to Jordanian folk tradition.

Quito's historic, main square dates back to the 16th century.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

A plaque marks the spot where the saint was shoved off the Charles Bridge and into the river.

Some claim these desert ruins are from the legendary "Atlantis of the Sands."

Traditional architecture and ancient irrigation systems are on display in this gorgeous mountain village.

A powerful cyclone once made one of the world's largest sinkholes completely fill with water.

These gnarly desert trees produce the prized aromatic resin traded along the ancient incense trail.

A section of the desert with an array of unusual sandstone and limestone formations.

American bombs, morbid memorabilia, and graphic photographs tell the story of the CIA-led “Secret War” from the Pathet Lao perspective.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

The world's seventh-largest coral reef contains an incredible amount of biodiversity.

This spectacular mosque houses the second-largest chandelier in the world.

A staggering number of rock carvings in an abandoned quarry.

Where artisans use centuries-old techniques to build traditional Arabian ships.

A sinkhole and now a swimming hole, too, full of dazzling turquoise water.

An imposing Omani fortress surrounded by date palm trees.

Nature's water park in the Wadi Bani Awf valley is full of pools flanked with cliffs and natural water slides.

Groups of prehistoric tombs that dot the mountains of northern Oman.

This bazaar is one of the oldest in the Arabian world.

Climb down into the largest sinkhole in Qatar.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

One of the holiest Shi'i shrines in Iran honors the life and death of a learned noblewoman who became a saint.

A nearly abandoned Jewish settlement perched atop a hill in the heart of Yemen.