Send a postcard while vacationing with Satan.

This sacred cavern, 400 feet deep, is home to millions of bats and an ancient burial ground.

Once thought to be the oldest living tree in the world, Methuselah was germinated before the Egyptian pyramids were built.

One of the world's oldest and most massive living organisms is a grove of quaking aspens.

Queen of the waterlilies, so big and strong it can support the weight of a human.

Two rocks in a perpetual kiss and one of "the most romantic spot in America."

Remember that scene in the Matrix, when Neo is in the big white room with all the weapons flying by? Well, this is what it would look like if he had wanted trees instead of guns.

The rocks in this arid basin leave trails of movement behind them.

Spring that emits water and fire at the same time is said to have remedial properties, and sparked its own religion.

A fiery crater has been burning in the Karakum Desert since 1971.

A former utopian healing center created by a huckster and built by derelicts.

This deceptively salty lake looks like blushing pink lemonade.

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.

This peculiar lake of pitch is so thick and viscous that one can walk on its surface.

Mother Nature outdoes herself with this stunningly beautiful set of caves carved into marble.

One of the deepest blue holes in the world.

Friction between grains of sand cause a curious "singing" sound.

Stunning wetlands ablaze with pink lotus flowers.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

Haunting and beautiful trees, doomed to die.

A lake with hundreds of ancient skeletons surrounding it. The surprise is what killed them.

Under the right circumstances, this waterfall in Yosemite briefly turns a luminescent fiery orange.

The glowing blue Nymphaeum of Emperor Tiberius.

The ghostly remains of an accidental sea.