This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

Northern Ireland's Brobdingnagian stepping stones.

Stepping away from the glitz of mobsters and casinos to learn about the other history of Vegas.

The ghostly remains of an accidental sea.

Odd outsider art installations surround a Gold Rush-era ghost town.

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

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

A bizarre house filled with an astounding array of collections.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

A huge musical instrument played by the ocean.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

Hollowed out cedar log tubs set in an ancient towering forest.

A world-class observatory in the California desert.

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

The first life claimed by this record-breaking peak wasn't lost to exposure or a fall but rather lightning.

The rocks in this arid basin leave trails of movement behind them.

The highest dunes in California are the most likely place in the area to hear the Singing Sands.

Once thought to be the oldest living tree in the world, Methuselah was germinated before the Egyptian pyramids were built.

"Only the devil could play golf here."

The lowest point in North America is home to an undrinkable pool surrounded by fields of geometric salt flats.

Nuclear waste dump site now an environmental sanctuary.

A "gravitational anomaly" located in the redwood forests just outside of Santa Cruz, California.

Haunting and beautiful trees, doomed to die.

Hidden among the multi-million dollar mansions in the Santa Cruz hills is a sanctuary for troubled birds.