Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

Commonly referred to as the most photographed Victorian home in the United States.

A hidden subterranean installation offers a view of the sky.

Home to the "Circus" trees created by Axel Erlandson.

Big gun installations, built over a massive cemetery, now abandoned & hidden in trees.

Nestled in the heart of San Francisco’s bustling Financial District stands a unique homage to the Mayan and Beaux Arts.

One of the most scenic stretches of road in America winds between some of the country's oldest trees.

Costumed elves and mountain bikers co-exist peacefully at this abandoned Christmas-themed adventure park.

A nondescript building that's been functioning as a speakeasy for nearly a century and a half.

A winding path built in secret on the edge of the continent.

A trash dump made beautiful by nature's power.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

Erotic art covers the walls of the largest ancient pleasure palace.

An unusual manor of stunning beauty, born out of a crippling disease.

Giant money stones of Yap.

An isolated dive site teeming with cnidarians.

The haunting ruins of Jack London's dream house.

One woman's Viking Castle on Lake Tahoe.

Air Force Academy Chapel made of 100 identical tetrahedrons works to inspire those of all religions.

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

Towering basalt columns, a creation of fire and ice.

Quite simply the largest tree in the world (by volume).

A graceful natural rock formation stands astride the point where the Gulf of California meets the Pacific Ocean.

The oldest teak bridge in the world is made from the remains of a royal palace.