Mysterious hillside with a continuously burning natural fire.

The abandoned palace stands as a wounded but proud beacon of Afghan hope.

Despite a history of destruction, this former citadel survives to document Afghanistan's oft overlooked history.

Once an impressive link to Afghanistan’s Buddhist past, now a sad reminder of intolerance towards other cultures.

What was once supposed to be the symbol of a shining Afghan future is now a bombed-out ruin.

This magnificent blue mosque in Afghanistan is surrounded by thousands of white doves.

An abandoned whaling station on an active volcano offers hot springs in Antarctica, surrounded by ruined giants of industry.

Natural time capsule containing an alien ecosystem.

Russian Orthodox church built on an Antarctic island.

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

Caves that can't seem to quit producing the remains of prehistoric humans.

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

Largest cave system in Africa.

The tallest residential building in Africa is an unsettling Brutalist monolith.

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

This slowly crumbling mansion was home to one of East Africa's richest and most powerful slave traders.

In Zanzibar, a historic 19th-century palace is a reminder of the world's shortest war.

Freddie Mercury's childhood home is now a monument to the iconic Queen rockstar.

A salty red wasteland in Tanzania is a breeding spot for endangered flamingos.

Stunning ruins of what was once the center of one of the greatest empires in East Africa.

An ancient Phoenician citadel once stood at the site where Queen Dido first landed, according to legend.

Founded in 670, this ancient mosque is an architectural time portal.

The ancient heart of Tunis is an enormous maze of narrow streets and alleyways.

Some believe this abandoned Brutalist masterpiece inspired George Lucas's Sandcrawler.