This hidden rooftop garden in downtown London offers a quiet respite from a bustling city.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

This upscale streetwear store is hidden behind a fake Snapple machine in the back of a deli.

These ancient ritual mounds are our best window into the culture of the ancient Mississippians.

These gutted monastery ruins still stand proudly in the middle of the Italian countryside.

Booker T. Washington's home at the Tuskegee Institute was a gem of splendor.

This domed temple was built in a hidden cave mouth as a refuge for sinners seeking absolution.

A quaint Russian village in the middle of a German metropolis.

A turn-of-the-century architectural marvel built on healing mineral springs and salt licks.

This extraordinary geological oddity resembles human-made pavement.

Gigantic Romanian salt mines used to heal respiratory conditions.

This German museum devoted to the simple wonders of salt is actually built over an old saltworks.

Home to Hollywood history and a very special salt crystal.

The world's oldest known salt mine.

The world's second largest salt mine, said to have been discovered by Alexander the Great's horse.

An underground city of salt.

Poland's oldest salt mine has nearly everything one needs to live underground forever.

A sacred lake composed of over 300 separate pools of highly concentrated minerals.

One of the world's largest salt caves is filled with fragile salt sculptures, salt rivers, and huge salt megadomes.

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

This salt marsh in Southern France is as pink as the flamingos that inhabit it.

Mine shafts and hard pastries await visitors at this massive mountain of salt.

The saltiest lake in all of Crimea is also the pinkest of the pink and teeming with life.

A tiny microvalley etched into the side of Knocknarea Mountain hides another world.