Gold Rush ship-turned-hotel buried underneath San Francisco's financial district.

Russian history in San Francisco.

The remains of a 12th-century chapter house in Golden Gate Park.

A man-made island in scenic San Francisco Bay.

San Francisco's most expensive hotel suite includes a secret passageway rumored to have been used by JFK.

Adolph Sutro's little-known, geographically inaccurate, deprecated monument.

The miraculous hydrant that saved the Mission District in 1906.

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

This partially buried wreck is one of the most complete of its kind but is only revealed when the sea allows.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

An overlooked and unassuming engineering marvel.

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

The remains of a ruined mansion memorialize the 1906 earthquake.

A 300-ship graveyard, with a few still visible at low tide.

Nestled in the heart of San Francisco’s bustling Financial District stands a unique homage to the Mayan and Beaux Arts.

A modern mechanical planetary system, part of a 10,000 year clock.

A nondescript building that's been functioning as a speakeasy for nearly a century and a half.

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

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

Buried for centuries, this hidden cellar is all that remains of London's medieval Whitefriars Monastery.

The largest collection of model trains in the world is actually run using full-size locomotive technology.

The world's shortest escalator doesn't seem to have any reason to exist other than to hold a world record.

Clean, cold drinking water flows from a nondescript pipe in a roadside rock face.

During the summer, surfers in Alaska take advantage of this inlet’s unusual water patterns.