A memorial to the only dog ever officially enlisted in the Royal Navy.

The Cape of Good Hope is not quite as low as you can go on the African continent, but it's still geographically significant.

A 19th-century relic of timekeeping.

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

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.

The remains of a 12th-century chapter house in Golden Gate Park.

Barely visible foundations remain where Stow Lake’s “observatory” once welcomed visitors.

This massive redwood tree has stood in Northern California for nearly 2,000 years.

The hands on this clock appear to be created by two workers sweeping debris into careful positions.

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

From the Difference Engine to the Cray-1, all under one roof.

In the basement of a San Francisco performing arts center, a small museum dedicated to the history of showgirls.

Under the shadow of its towering parent tree, a rare specimen of sequoia produces ghostly white leaves.

A 19th-century California philanthropist is entombed beneath the telescope he funded.

The world's first permanently occupied mountain-top observatory continues to report on the stars.

Designed to resemble foreign architecture, this mosque-looking structure was used to pump water to a royal fountain.

A humble garage, world-famous for being the epicenter of a technology revolution.

In 1998, Larry Page and Sergey Brin briefly ran their fledgling company from this Silicon Valley garage.

The first high-tech company in the valley that actually worked with silicon devices.

The longest burning light bulb in the world.

A gathering of green robots at the Googleplex.

One of the largest free-standing structures ever built, this dirigible hangar is now simply a giant skeleton.

This airfield played a key role in both World War II and the Cold War.

A statue commemorate Tommie Smith and John Carlos's brave protest at the 1968 Olympics, a watershed moment for civil rights.