Once a favorite playground for the world's most illustrious guests, Hotel Nacional's secret weapons and bunkers reveal a more menacing side to its golden history.

Scientists use one of the saltiest bodies of water on Earth as a terrestrial base for studying water on Mars.

The birthplace of the very first human resident born in Antarctica.

One of the most extreme deserts in the world, these snow-free valleys harbor life, despite the hostile environment.

Largest sub-glacial lake ever discovered.

Naked scientists race around the pole in the frigid cold to try to join Antarctica's exclusive 300 Club.

The world's largest neutrino telescope searches for secrets of the universe at the South Pole.

Russian Orthodox church built on an Antarctic island.

One of the world's southernmost bars.

Fire meets ice at the southernmost volcano on Earth.

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

The true jewel of Africa's west coast known as "Africa's Last Eden."

At Ghana's largest wildlife refuge you feel like you're right in the animals' backyard.

This series of rope-style bridges brings visitors into a jungle layer that is usually reserved for birds and monkeys.

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

The first mosque in Ghana is known as the "Mecca of West Africa."

Early Islamic mosque with several strange conical domes.

A fortress-like granary that has been continually in use for more than nine centuries.

A beautiful oasis town dating back to the Roman period still serves as reprieve from the brutal summer sun in Libya.

Fabulous formations, weird and wonderful wildlife.

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

Ancient Manuscripts showcase the civilization of West Africans during the Middle Ages.

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

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