An unfinished tomb carved into a giant boulder in the Arabian Desert.

An annual two-week festival near the city of Riyadh when Saudis let their hair down.

An imposing Omani fortress surrounded by date palm trees.

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

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

This giant underground cave chamber can only be accessed through a small opening at the top.

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

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

This picturesque island graveyard is the final resting place of dozens of notorious pirates.

Giant disc-shaped gate took 20 men to close off this city in Madagascar.

Fabulous formations, weird and wonderful wildlife.

The centuries-old trees lining both sides of this dirt road may become Madagascar's first natural monument.

This underwater cave in Madagascar is home to what is thought to be the country's largest fossil graveyard.

Dating back to 1812, this is the oldest racecourse in the Southern Hemisphere.

Only two of these trees remain in the natural world, found high in the cloud forest of the island of Mauritius.

The “Thumb” of Mauritius provides a 360 degree view of the entire country.

Réunion Island's highest point is a 2 million-year-old volcano and a paraglider's paradise.

At the center of an island in the middle of the Indian Ocean is a deep chasm ringed by tall waterfalls.

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

Only hotel where you can legally launder money.

The interior of the Overlook Hotel in "The Shining" was based on this Yosemite original.

Numberless clock creates a meal of time for the dreaded, insectile Chronophage.

Used as an example in one of the first dictionary entries for "museum" in 1706.

An extraordinary collection of scientific instruments - and Einstein's chalkboard - inside the world's oldest purpose built museum building.