This abandoned sea fort has become an accidental bird sanctuary.

The land is home to swimming ponies and a legendary 18th-century treasure.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

The taxidermy remains of the most popular pony in children's literature.

Thomas Jefferson's estate is home to hundreds of varieties of historic fruits and vegetables.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

The century-old bell and clock tower at UC Berkeley is the third-tallest in the world, and has fossils.

Where the alchemists dream of transmuting base metal into gold was actually achieved.

This subtle Berkeley paving stone actually marks off a lawless tube of air that extends into space.

San Francisco's first World's Fair, dedicated to the wonders of California.

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

Golden Gate Park's historic collection of plants.

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

Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.

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

Olfactory delights in San Francisco's Botanical Gardens.

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

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

An artsy hidden staircase leads to breathtaking views of San Francisco.

A huge musical instrument played by the ocean.

The fine fabric handwoven at Biltmore Industries was once coveted around the world.

The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

I-95's Tijuana-style celebration of kitsch at the Carolina border.