Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

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

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

These delicate buggers are some of the rarest fossils that have bubbled up from the Tar Pits.

A strange house built only at night, with rumored mystic inspiration.

A prohibition-style speakeasy takes up residence in the last Victorian residence in Hollywood.

The rocks in this arid basin leave trails of movement behind them.

Get lost in this haunting fairytale art walk through a man-made eucalyptus grove.

A 140-year-old castle with underground caves hidden in San Francisco.

World's largest collection of serial killer artwork and other macabre exhibits.

Perfect your fly fishing technique on their practice ponds.

Masterful ceramic fountain and map of the Pacific Basin.

An elaborate gift from Claus Spreckels is now a piece of San Francisco history.

This residential door allows San Francisco muggles a glimpse at the wizarding world.

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

Radioactivity still cause for concern at this urban explorer's paradise.

Over 315,000 preserved amphibians and reptiles in jars.

A library built during San Francisco's pioneer times is a student's retreat, bibliophile's sanctuary, and chess player's delight.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

The ghostly remains of an accidental sea.

World's largest collection devoted to one fruit.

This strangely vacant Western amusement seems to be an empty tribute to residents of Lucerne Valley.

Three generations of intrepid collectors display their curious artifacts in a homemade museum right next to the caves they discovered.

A pair of trees near a Hong Kong shrine are said to grant wishes, but only the ones they hold on to.