Every year, over 25,000 monarchs overwinter in Pacific Grove.

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

The first safe in this California town had to hold all the gold.

The oldest U.S. Government building in California, and it's State Historic Landmark #1.

Steinbeck's old stomping grounds, immortalized in Cannery Row.

The graffiti-covered remnants of a former triangulation station are balanced precariously on this California peak.

Concrete strongholds stand guard over the Golden Gate.

Forgotten and then destroyed by fire, this was once one of the largest saltwater swimming pools in the world.

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

Once the largest windmill outside of Holland, with enormous 114 foot sails.

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

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

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

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

This controversial depiction of the "Founder of California" looks as though it was sculpted from mashed potatoes.

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

A classically inspired temple in Redwood City.

Once the fastest ship from San Francisco to Tahiti, the Galilee now lays in pieces in three different cities.

Visible below the waves are memorials to the city's Gold Rush dead.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

Only hotel where you can legally launder money.

Floating man-made island and upscale restaurant.