Four alabaster giants contemplate the tides on the shore of Denmark.

This fortress was designed to prevent a Nazi invasion but was never used.

This odd Chilean waterfall-cano hotel must be entered via a rope bridge.

Nature puts on a spectacular show at this blowhole on the eastern side of Gran Canaria.

Hundreds of caves once used to store grains and animal feed.

The world's largest single-aperture telescope resides in the Canary Islands.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

This "common-as-dirt" museum celebrates the glory of normalcy.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

The show's fictional Korean medical camp was created in the Santa Monica hills.

Just a few miles off the western coast of Ireland lies an isle steeped in Irish literary history.

Stockholm's deepest subway station is also a stunning ecological wonder.

Crooked windswept pines give this old forest an enchanted and magical look.

The beautiful 1920 Pantages Theatre remains hidden just underneath the LA Downtown Jewelry Exchange.

Visitors flock to see this church tower's unintended feature: It happens to resemble a giant chicken from multiple points of view.

There might not be much left of these Irish ruins, but their linguistic legacy is still going strong.

This wondrous waterfall rushing down a green-covered mountain wasn't discovered until 2010.

Romania's "Red Ravine" is a little-known natural wonder that bears a resemblance to the Grand Canyon.

A meow-velous tribute to a beloved street cat, made famous on the internet.

This shuttered power plant is now Turkey's first industrial archaeology museum.

The ornate miniature mansions were built for Istanbul's feathered residents.

A gorgeous, Gaudí-esque stairway constructed in the city of Istanbul by a prominent Jewish family.

Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

This unique temple complex remains off the typical tourist trail.