This huge pile of volcanic boulders hides a stunning network of secret grottoes.

Rumored to be the famed pirate's lookout tower, this historic stone structure is now just watching for tourists.

Rusting, graffiti-covered tanks litter the beach of this island, once used by the U.S. military for target practice.

Bizarre living fossil only grows in a small chunk of the Namib Desert.

Unexplained bald patches in the landscape grow and recede over time, as though they are somehow alive.

A desert that rolls right up to the ocean, where it's so dry animals live off the fog.

This "dead marsh" sits among the largest sand dunes in the world, a forest frozen in time.

An obelisk marks the spot where a British explorer's heart was buried before the rest of his body was transported to England.

One of the largest concentrations of rock paintings in Southern Africa.

The world's highest and most dangerous infinity pool lies at the precipice of Victoria Falls.

These naturally balancing rocks were pictured on every Zimbabwean banknote, up to the 100 trillion-dollar note.

The largest prehistoric ruins south of the Sahara, once a powerful center of international trade.

Wondrous stalactites house thousands of bats in these African caves.

There is only one place in the world where the corners of four nations come together.

Tiny pyrophyllite spheres from 3 billion years ago.

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

Raging waters have created a strange geological site that looks like something off of a progressive rock album cover.

Formerly known as the Malay Quarter, Bo Kaap is a colorfully-painted suburb located in the “Mother City” of South Africa.

This African beach is home to thousands of rare mainland penguins that are known for their annoying voice.

A graceful natural rock formation stands astride the point where the Gulf of California meets the Pacific Ocean.

A hidden treasure of an abandoned city lies deep in the jungles of Campeche, Mexico.

The largest cave shaft in the world is home to thousands of birds and popular with BASE jumpers.

An elaborate Mayan city shrouded in alien conspiracy revealed the tomb of Pacal the Great.

High atop a Mexican rainforest mountain, this ancient pyramid once drew pilgrims countries away.