Ozymandias’ time-keeping temple.

These Egyptian statues have survived for 3,400 years and were an acoustic wonder of the ancient world.

An endless sea of white conical domes.

An ancient city exhumed from the depths of the ocean.

A powerful tribute to the victims who suffered under Ethiopia's most devastating regime.

Supposedly this Ethiopian chapel holds the Ark of the Covenant, guarded by virgins who cannot leave the building.

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

Ethiopia's "smoking mountain" is in one of the hottest regions on the planet and is home to two lava lakes.

The world's first and only natural nuclear reactor.

Where thousands of slaves passed through the "Door of No Return."

This colonial fort is an intriguing example of Renaissance military architecture.

A salty cave excavated by elephants and the location of a deadly disease vector.

Abandoned city hidden from the world by tropical forest and isolation on the coast of Kenya.

Empty since 1989, now falling into ruin.

Surrounded by a smudge of dark earth, this isolated volcano sits in stark contrast to the surrounding Sahara.

This triumphal arch is the only fully standing structure that remains from Roman-era Oea.

Now home to nothing but a weather station and a landing strip, a group of enslaved people were marooned on this tiny island for 15 years.

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

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

A hollowed-out baobab that became the horrific final resting place of leprosy sufferers, with gruesome evidence to prove it.

One of Western Africa's oldest mosques, this Timbuktu icon has stood for nearly 700 years.

These homes carved into the mountains seem to defy the laws of nature.

The most important and best preserved remnant of West Africa's powerful Songhai Empire.

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