One man's exploration of the human form, including the bizarre and delightful "Man Attacked by Babies."

Frida Kahlo's childhood home, now a museum of her life and works.

One of only two commuter aerial tramways in the United States.

Massive crater in central Oregon.

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

A massive volcanic plug is now a protected area that hosts a number of bird species.

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

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

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.

A working model of the entire San Francisco Bay and much of the Sacramento River Delta, complete with regular tides that change every 14 minutes.

Thousands of turbines whir at at the origin of North American wind power.

Once close to extinction, there is no shortage of elephant seals on the beaches of Año Nuevo State Park.