Quite simply the largest tree in the world (by volume).

Decommissioned experimental solar facilities that pioneered solar energy technology.

This giant temperature attraction created some giant electric bills.

The historic building's ornate stained glass fixture has survived the devastating 1906 earthquake, ensuing fires, and multiple redevelopment attempts.

A pair of mutilated bronze octopuses slump at the base of the monument honoring California's admission to the U.S.

San Francisco's oldest surviving monument and meeting place for 1906 survivors.

This residential door allows San Francisco muggles a glimpse at the wizarding world.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A giant open-air sculpture made of over 200 full-sized boats.

A three-story, three-dimensional hobo clown in a tutu welcomes CVS shoppers.

After starting as a whimsical tourist attraction that eventually found its way to ruin, these renovated canals offer a lush and exotic locale on the Pacific Coast.

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

This iconic L.A. bookshop is housed in an abandoned bank—both symbolic and chic.

This life-size replica of the Statue of Liberty's flame is also a tribute to Princess Diana by default.

An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

A surrealist timepiece by the artist of melting clocks.

Site of a classic 19th-century physics experiment to prove the earth is rotating.

This museum houses an imposing skeleton army comprised of creatures great and small.

This modest marker near Notre Dame identifies the very center of Paris.

Notorious artist squat renovated into legal studios.

This bridge was constructed from the rubble of the infamous Bastille.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

This Parisian café sticks almost exclusively to an ethos of reuse.

A series of abstract, silly sculptures represent the works of a great modern classical composer.