The ghostly remains of an accidental sea.

These lush groves of fan palms rise up like oases out of southern California's Colorado Desert.

The remnants of an early automobile route across shifting sand dunes can still be found in the deserts of Southern California.

Wee (and not so wee) footprints that insects and reptiles of the Paleozoic Era left behind.

The state bird of New Mexico, constructed entirely out of garbage.

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

Some of the Old West's most notorious outlaws frequented this mining town.

An early 20th-century fruit warehouse home of an artistic and cultural renaissance in northeastern Washington.

This ruined fort and statue are a testament to the last king of Kaua‘i’s savvy diplomacy skills, which briefly brought Russians to Hawai‘i.

It's believed Matilda Fitzwalter's life was the basis for the famed literary figure.

More than a century old, this trading post resides in the Navajo Nation.

It took over 100 years to decode this enigmatic epitaph for two buried brides.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

Monty Python fans will recognize this abandoned mine as the Cave of the Killer Rabbit of Caerbannog.

The cheese slicer may be a Norwegian invention, but the biggest ones in the world are found in Sweden.

A hidden slot canyon in the southern Nevada desert makes an unexpected oasis and scenic hike.

A graveyard for early settlers, sometimes called Old Pioneer Cemetery, hidden in the woods on a hillside.

Described by William Wordsworth as a "World of Wonder."

An exercise in patience and imagination, where Mother Earth turned common stuff into precious hidden treasures.

"Enter and be entertained or annoyed by Dada in Walla Walla."

This large Sitka spruce that appears to be floating in mid-air, has defied logic for years.

A bike being "eaten" by a tree is the real Vashon legend behind popular children's book, "Red Ranger Came Calling."

A tunnel with windows, so you don't miss out on the impressive views.

This prehistoric sinkhole lured exclusively male mammoths to their death, much to the delight of science.