An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

The secret city built by the Manhattan Project.

This funicular railway rumbles along for a mile up the nearly vertical face of Chattanooga’s Lookout Mountain.

If New Orleans is the birthplace of the "cocktail," why does their own museum of cocktail memorabilia beg to differ?

The record holder for the world’s largest peach.

The world's smallest park was dedicated in 1948 as the only colony for leprechauns west of Ireland.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

Quite simply the largest tree in the world (by volume).

This naturally heated mountainous creek has created a group of neon blue pools of potentially deadly boiling water.

Beneath a Virginia City bar is the entrance to an abandoned gold mine.

A dwindling menagerie of anthropomorphic oil derrick animals still dot the barren California landscape.

A tree grown from astronaut seeds which were exposed to cosmic rays.

Life in this isolated, hilltop lighthouse was lonely, but it sure was lovely.

One poet's handmade, anachronistic home.

Home to the "Circus" trees created by Axel Erlandson.

A pair of pure white felines guard the entrance to a spot of California real estate established as an artist's haven.

Elephant seals and sea lions have turned the abandoned buildings on this island into their endangered love shack.

Once close to extinction, there is no shortage of elephant seals on the beaches of Año Nuevo State Park.

A New England-style lighthouse along California's beautiful Highway 1 gets a re-do.

The fossilized remains of ancient California redwoods.

Commonly referred to as the most photographed Victorian home in the United States.

A man-made island in scenic San Francisco Bay.