The largest drain hole in the world.

Condemned US Navy seaplane control tower turned officers’ club sits atop Yerba Buena Island.

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

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

Once the gateway to the utopian dream-village of a Civil War embalmer.

This strange geological landscape erupts with sudden bursts of water.

The glacier tucked within a New Zealand rainforest.

A creepy steel gremlin has protected the Bay Bridge since 1989.

An enormous illuminated figure dances on the Las Vegas strip.

An enormous artwork that colorfully celebrates over 150 years of US military achievements.

A man-made island in scenic San Francisco Bay.