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

Once the largest windmill outside of Holland, with enormous 114 foot sails.

There is no trying to fall in love with this Star Wars fountain, you just do or do not.

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

A huge musical instrument played by the ocean.

Prone to disastrous fires, the city of San Francisco has the Guardian, a fireboat gifted by residents, to watch over them from the bay.

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

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

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

A promotional sun clock on the site of San Francisco's great raceway.

This grinning pup statue is all that's left of what was once a ubiquitous Bay Area diner chain.

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

Concrete strongholds stand guard over the Golden Gate.

A winding path built in secret on the edge of the continent.