America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

A monument celebrating the idea of reaching inaccessible places.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

This blowhole is supposedly caused by a trapped monster.

This failed condo development was reborn as a street art hub.

A museum commemorating the Donora Smog, which killed 20 people in October 1948 and sparked national outrage over air pollution.

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

This church in Pittsburgh is home to the largest collection of religious relics in North America.

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

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

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

Furniture tries to escape an abandoned building in San Francisco.

These subterranean storage areas hold emergency water reserves.

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

A wall of chewing gum moonlights as collective art.

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

The first life claimed by this record-breaking peak wasn't lost to exposure or a fall but rather lightning.

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

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

An "anarchical" no man's land, complete with garbage sculptures and a hobo-run "Landfillian Library."

This subtle Berkeley paving stone actually marks off a lawless tube of air that extends into space.

Explore 10 acres of environmental sculptures.

Experience a quartz crystal sound bath inside a storied, all-wood sound-chamber.

An eclectic trailer park retreat in the middle of the California desert.