Steinbeck's old stomping grounds, immortalized in Cannery Row.

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

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

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

The randomness of this wall of lava lamps helps encrypt up to 10 percent of the internet.

A fantastic castle rumored to be the birthplace of King Arthur.

It is said the legendary wizard once lived in this sea cave beneath Tintagel Castle.

One of the largest free-standing structures ever built, this dirigible hangar is now simply a giant skeleton.

From the Difference Engine to the Cray-1, all under one roof.

The model behind the iconic 3D test model.

The giant birds honor two native North American species.

This alley in downtown Chicago held the bodies of over 600 people after the fateful Iroquois Theatre fire.

Pennsylvania's own Roswell-style UFO mystery.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

Most-visited and most-photographed slot canyon in the American Southwest.

In an odd geographic anomaly this city borders two different states on opposite sides of town.

One man's real life disfigurement inspired a lasting local legend surrounding an eerie tunnel.

A model of a dinosaur that was named for Andrew Carnegie stands outside the museum that also bears his name.

Sections of the iconic limestone columns have been left uncleaned as a reminder of the city's polluted past.

The largest university building in the West is a gothic masterpiece containing dozens of theme rooms based on different countries.

This public park was the site of the largest civilian disaster of the Civil War.

A restored Pittsburgh house of God has been converted to a marvelous house of suds.