One of the largest and oldest caravansaries in Persia.

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

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

Iran's colorful terraces are a rare geological masterpiece.

Taxidermy of a famous hippo who spent three years walking over a thousand miles across South Africa.

Nelson Mandela lived here with his family from 1946 until his arrest in 1962.

Over 60 species of birds inhabit this colorful aviary park in South Africa.

This small monument marks the divide between the Atlantic and Indian Oceans at the southernmost tip of Africa.

An ancient impact crater on the outskirts of Pretoria.

A sobering account of the vibrant multicultural neighborhood that was destroyed under apartheid.

The spot where the first living specimen of the coelacanth was discovered.

A massive rock in the surf steeped in legends.

Fascinating collection of Khoisan rock engravings, still situated in their original setting.

These otherworldly caverns form Earth's oldest known cave system.

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

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

An imposing Omani fortress surrounded by date palm trees.

You have to know where to look in this rather ordinary-looking square to find hints of its past as a dissidents' cemetery.

A replica of a beloved, delicately-balanced granite boulder.

A pocket of serenity in hectic Buenos Aires, complete with a peaceful courtyard and massive library.

A small but industrious mining operation that allows visitors to touch precious gems while they are still in the rock.

From 135 feet high riders plunge down the world's tallest freestanding body slide at 65 mph.

You feel like you're in a forest, but you're actually walking amidst the branches and trunks of a single giant tree.

Bangkok celebrated its shifting monarchy with a militaristic homage to democracy.