This geothermal hot spring hides beneath a slowly growing mineral dome.

A little-visited waterfall in an otherworldly landscape.

A half-mile long and three stories high, this bridge over the Des Moines River Valley mimics a descent into a mine shaft.

A breathtaking 19th-century trail overlooks Lake Tahoe.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

A grove of "candelabra redwoods" deep in California's Lost Coast.

The sound of swaying stalks in this stunning grove has been named a governmentally recognized sound.

An emerald-green grotto just a short trip from Austin.

A towering Art Deco movie palace made to look like a Mayan temple.

This quirky museum has a collection of more than 15,000 bobblehead dolls.

A house carved into a rock in the 1940s.

The "Fun Spot of the Desert" is now a haunting ruin, and a reminder that putting a water park in a desert is a bad idea.

This public space is speckled with the eerie remnants of a defunct amusement park.

Cryptid lake monster honored with its own monument.

A popular place to pick up prehistoric coral fossils from the time when Michigan was an ocean.

Deep below the dry landscape of Bahia, a cave with intense blue water to float in.

A WWI fighter plane and turn-of-the-century penny candy shop are among the unexpected features of this Financial District building.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

An absolutely beautiful 200-foot stained glass installation traces the evolution of knowledge.

An architect transformed this abandoned cement factory into his castle-like workshop.

The land is full of geologic eye candy, such as otherworldly spires, mushroom-shaped hoodoos, and prehistoric fossils.

Legends of treasure and spirits flow from this this fairy tale-like oasis.

Halloween spirit is alive and well in this small town, where residents race motorized caskets in a yearly tradition.

For six months of the year, three giant mirrors direct a pool of sunshine onto this otherwise occluded town.