Concrete strongholds stand guard over the Golden Gate.

Two rocks in a perpetual kiss and one of "the most romantic spot in America."

The oldest lighthouse on America's west coast no longer needs keepers, yet they maintain the site anyhow.

Only hotel where you can legally launder money.

The southernmost outpost of the Russian Empire in colonial America.

This quirky UFO-shaped curiosity is often mistaken for the airport’s control tower.

A glimpse into the lives of the the Miwok and Paiute people in Yosemite National Park.

An historic and oft-filmed spot for musclebound iron pumpers on the Pacific coast.

Haunting and beautiful trees, doomed to die.

The oldest continuously operating Catholic school west of the Mississippi.

A rich history stashed behind an unassuming door in the heart of Gold Country.

A fine mixture of the old and the new topped with an art deco neon spire.

The Empire Mine is "one of the oldest, largest, deepest, longest and richest gold mines in California."

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

An elaborate gift from Claus Spreckels is now a piece of San Francisco history.

The Jewish section of the famous Boothill Graveyard was abandoned for nearly 100 years.

A stone pillar marking the location of the westernmost battle of the American Civil War only honors one side of the conflict.

A monument to the one-armed geologist who led the first documented expeditions through the Grand Canyon.

Perhaps the most spectacular grotto along the Algarve coastline.

Formerly known as Saville Theatre, this mid-20th-century entertainment hub includes an ornate frieze.

This home designed for chocolate magnate Antoni Amatller is an exquisite treasure-box of Catalan Modernism.

A discarded movie prop that was the original monolith for "2001: A Space Odyssey."

Three rooms of bones, curios, and one artist's collection of natural artifacts create this intriguing museum.

This quirky collection is an interactive exhibit crammed with creative contraptions and tinkered-with toys.