On the Oregon coast there is a natural hole that seems to be draining the sea.

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

This natural wonder drops 16 stories straight down through rare flora and streaming waterfalls.

Stories of sightless fish and ghostly cowboys are only a fraction of the legends surrounding this Kansas sinkhole.

The perfectly named cave drop is the deepest in the continental United States, almost matching the height of Seattle’s Space Needle.

A striking, menacing sandstone peak towering above a landscape that's equal parts Mordor and the Moon.

Mural made of 100,000 pieces of hand blown glass, and until recently, the largest glass mural in the US.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

This lab's maddening silence is good for business but bad for sanity.

The scuba diving training facility was named for the steam that rises from the cave's chimney.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

Scores of vintage street lamps shine along L.A.’s Miracle Mile.

This incredible collection of vintage pinball machines can be played at 25 cents a pop.

The world's longest known cave system.

Make your reservation to have coffee with some kitties.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

This frequently-photographed waterfall takes only a short hike to visit.

This unique structure in suburban Austin is made up entirely of other people's castaways, and constantly changing.

This naturally-sourced hot spring is now home to a clothing-optional resort.

Ride the subways of yesteryear.

Where beautiful signs live on forever.

A breathtaking array of ancient Pueblo structures and artifacts counterintuitively preserved by neglect.

This little museum is built on a theater that was once a wildly elaborate speakeasy.

A dilapidated dock tells the story of Titanic's missed arrival.