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

World's first "penitentiary," meant to be humane, drove men insane.

World's largest collection of serial killer artwork and other macabre exhibits.

Rippling sand dunes frozen in the Arizona rock.

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

A psychedelic labyrinth on the San Francisco bay.

Look closely and you’ll notice that the color changes a third of the way up the tower.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

Home to a vast and influential collection of Shakespeareana.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

A wondrous old library overlooking the nation's capital.

Home to items never before seen by the public.

They call this long foot bridge a swinging bridge, but really it's the bouncing you have to watch out for.

The largest drain hole in the world.

This bridge is haunted by the ghost of a distraught mother.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

Once the "Eighth Wonder of the World," this iron railroad bridge was decimated by a tornado.

This Colorado hiking trail provides a small gold mine of abandoned gold mines.

A natural gas leak provides a flickering flame beneath a waterfall.

The second largest waterfall by volume in the U.S., Willamette Falls is outdone only by Niagara in the amount of water that is pushed northward.