Macabre astrological automaton clock dating to the late 1400s.

A preserved Nazi labor camp now has a Holocaust museum on site and memorials to the thousands that died while imprisoned at the camp.

A man-made slag heap that you can "ski" down, and is home to the world sandboarding championships.

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

Golden Gate Park's historic collection of plants.

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

This private residence was the template for one of the most beloved television homes of all time.

San Francisco's urban bison herd has persisted in the face of extinction, development, and disease.

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

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

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

San Francisco's newly reopened hands-on science museum.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

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

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

A huge musical instrument played by the ocean.

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

A church of bones, decorated with 40,000 human skeletons.

120 mortarless pagodas built by one Korean hermit.