The long, arduous journey of the stones of the Abbey of New Clairvaux.

Home of what was the largest hydraulic mine in the world, producing gold and the first diamonds in the U.S.

A train tunnel that was made obsolete by the dam it helped create.

Law-protected wreckage serves as a peculiar memorial for an almost forgotten World War II tragedy.

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.

This former factory contains an amazing collection of around 400 mint-condition Nissan cars.

With its vast selection of books, comics, and records, this nearly 70-year-old open-air market always rewards the patient browser.

Museum housed in underground tunnels that date back to Buenos Aires's earliest settlements.

A tower devoted to — and modeled after — the Divine Comedy.

Buenos Aires' city of the dead contains some very famous remains, including Eva Perón.

A gateway to a mysterious network of underground tunnels.

Another of California's unused Cold War missile defense complexes has become a graffiti gallery.

The graffiti-covered remnants of a former triangulation station are balanced precariously on this California peak.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

Tiki luxury on Nob Hill.

Big gun installations, built over a massive cemetery, now abandoned & hidden in trees.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

A collection of memorabilia from the Beat era in the back of a San Francisco bookstore.

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

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

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

A collection of 20th-century automata, penny arcade games, and musical contraptions.

This restaurant offers the original California cuisine.

The century-old bell and clock tower at UC Berkeley is the third-tallest in the world, and has fossils.