A historic observatory precariously perched at the "Top of Europe."

During World War II, Austria's oldest salt mine was used to store thousands of pieces of stolen artwork.

Narrow-gauge railway with its own personal power grid.

Ruins of a German Castle on top of a towering stone pillar.

A mansion where wonders of Christmas are celebrated all year long.

The first museum in the world devoted to sexual gadgetry.

During World War II, the Nazis repurposed this beer cellar to store stolen artwork.

The birthplace of the builder of the Statue of Liberty is now a museum dedicated to his work.

One man's stunning attempt at eco-friendly living.

The last bastion of Roman presence north of the Alps looms over a German town.

The oldest Jewish cemetery in Europe survived Hitler's Germany.

One of the world’s largest cave systems houses legends, concerts, and wondrous rock formations alike.

A 1940s nuclear reactor built to produce plutonium for the Manhattan Project.

Concrete construction materials turned into a fashionable capsule hotel in rural Mexico.

Cave carved out of a huge snow drift collapsed killing one and injuring five in July 2015.

While these wooden totems bear a striking resemblance to First Nations artwork of British Columbia, their actual origins lay on the opposite side of the Pacific Ocean.

The world's smallest park was dedicated in 1948 as the only colony for leprechauns west of Ireland.

These cinderblock farmhouses were actually World War II radar stations in disguise.

No one knows how this Pacific Northwest spruce tree came to have so many trunks.

A psychedelic labyrinth on the San Francisco bay.

Orcas on display and in the water.

This long, dark tunnel is open to hikers, but those without lights are known to get confused even on the straight path.

Seattle's super-sized cowboy apparel once belonged to a themed gas station that wrangled in herds of tourists.

This three-story antique market and curiosity emporium claims to be "the largest singly owned antique shop in the Pacific Northwest."