In this historic region, homes and churches are carved into ancient volcanic rock formations.

These tourist trap caverns are said to be the former home of a legendary Pennsylvania Hermit.

Constant erosion has created a surreal landscape of bleached and preserved fallen trees.

The ruins of this gorgeous clifftop castle look like something from a fantasy novel.

Monasteries on rock pillars, once accessible only by frayed ropes.

The longest living non-clonal organisms on Earth.

A once grand hotel is being retaken by the wilderness it once capitalized on.

A hidden beach at the end of a tunnel of mangrove trees.

This rare example of a "tidefall" is a spectacular drop from the cliffs down onto the beach.

A natural gas leak provides a flickering flame beneath a waterfall.

Each spring, a dreamlike carpet of bluebells overtakes the forest floor.

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

San Francisco's urban bison herd has persisted in the face of extinction, development, and disease.

Paranormal investigators claim this abandoned asylum is the most haunted spot in the eastern U.S.

Even Henry David Thoreau found this glacial pothole irresistible.

This abandoned bridge to nowhere stands secluded in the woods of a Cleveland suburb.

Bad farming practices caused this unnatural natural wonder.

A taste of Middle Earth, in the middle of the Bayou City.

Beautiful Victorian buildings from L.A.'s forgotten architectural past.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

The United States’s oldest funicular railway glides up and down a steep Pittsburgh street.

Ring the bell to enter a bar that looks equal parts museum and old curiosity shop.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

The Grand Canyon of Texas.