The headquarters of a secretive order is also a beautifully-designed park.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

This Big Sur waterfall drops 80 feet directly into the Pacific Ocean, and inspired the hillside house up top.

One of the oldest producers of hand-folded fortune cookies still uses its original secret recipe.

A modest reminder of treacherous waters at the Golden Gate.

Faceless white figures loom over the city from the rooftop.

A historic hotel that made a cameo in Hitchcock's classic film has no intention of letting guests forget its fame.

Air Force Academy Chapel made of 100 identical tetrahedrons works to inspire those of all religions.

This Boeing KC-97 tanker is now a restaurant for aviation lovers.

A dazzling display of red rocks weathered into spires and hoodoos.

One of the world’s largest collections of petroglyphs records 2,000 years of human activity.

A 19th-century cabin built into a hollowed-out Sequoia tree.

Rusty pieces of metal jutting out of a breakwater are all that's visible of the 12,500-ton ocean liner that capsized just off the beach.

A Roman-inspired temple once controlled half of San Francisco's waters.

Hidden in the Santa Ynez Mountains off Highway 154, this tiny restaurant once served as a stagecoach stop.

A 300-ship graveyard, with a few still visible at low tide.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

A winding path built in secret on the edge of the continent.

The key to turning shifting dunes into the green oasis of Golden Gate Park.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

This hidden fire lookout offers spectacular views of Sequoia National Park.

The largest wildlife crossing in Utah allows local fauna to safely traverse the six-lane Interstate 80 at Parleys Canyon.

Few things look more out of place than the electric blue ponds in the reddish-brown desert of Utah.