Unusual, mushroom-like rock formations caused by weathering and water erosion, set to disappear, according to geologists.

This unassuming museum's slogan translates to “there is a limit of sadness, anxiety has no limits."

This massive concrete sculpture is said to be the heaviest communist monument on Earth.

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

American soldiers discovered Europe's best one-liner at the end of World War II.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

Mysterious spherical rocks in the semi-desert of western Kazakhstan.

The world's largest natural arch was forgotten for over 50 years after its discovery.

Be careful not to get trampled at this lively two thousand-year-old market.

Extremely isolated Silk Road caravanserai in the middle of nowhere.

The inspiration for H.P. Lovecraft's horror stories and Batman's Arkham Asylum is now a condominium complex.

Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.

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

A walk through the historic city center, under the streets of Seattle.

These fantastically named natural pools look like something out of a Scottish myth.

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.

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

It should come as no surprise that the best view of the Hollywood sign is from Batman's lair.

The ghostly remains of an accidental sea.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

A toxic ghost town sitting atop a massive coal fire.

A trash dump made beautiful by nature's power.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

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