Of all the origin stories for weed's secret code, this one likely has the goods.

The first AIDS memorial chapel in San Francisco and one of only a few in the U.S.

A huge collection of rocks, gems, and crystals.

This San Diego museum, housed in a former Navy training facility, is dedicated to preserving women’s historic achievements.

About 80% of all U.S. avocados are descendants of Rudolph Hass's glorious tree.

A raised boardwalk winds through a thicket of stunted, century-old trees no more than nine feet tall.

A popular winter vacation destination for migrating monarch butterflies.

Art from the latest counter-culture; kids who dye their hair blue and believe the future will be a post-apocalyptic water world.

Celebrating the transformation of trash into objects of beauty.

San Franciscans leave gifts and messages for the magical beings that live behind the tiny, mysterious door installed on a tree in Golden Gate Park.

A library and museum dedicated to typography.

Tenacious mummies survived dental problems, eternal entombment, and more than their fair share of devastating fires.

The randomness of this wall of lava lamps helps encrypt up to 10 percent of the internet.

A collection of memorabilia from the Beat era in the back of a San Francisco bookstore.

The fossilized remains of ancient California redwoods.

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

San Francisco's oldest surviving monument and meeting place for 1906 survivors.

Dozens of lights dangle from the branches of what may be the brightest tree in Los Angeles.

The remains of a ruined mansion memorialize the 1906 earthquake.

This massive redwood tree has a hole in the base big enough to drive through.

This glamorous old building is said to have inspired the Tower of Terror.

A modern mechanical planetary system, part of a 10,000 year clock.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

One of the most scenic stretches of road in America winds between some of the country's oldest trees.