A self-built castle made by a mysterious man.

Open since 1938, this diner has kept its fountain, malt machine, and all the gum that greasers left beneath its counter.

This striking public art installation is suspended above a public park, designed to gently move in the breeze.

A mile-long audio-guided walking tour preserves an iconic era of Portland soul music.

Forever immortalized in concrete, this Simpsons etching was crafted by show creator Matt Groening.

Crafted in 1911, this steam locomotive spent its entire working life in Flagstaff.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

This ancient cave is home to a museum, bar, and is filled with fluorescent minerals.

Not your typical pet cemetery.

A tunnel with windows, so you don't miss out on the impressive views.

The unusual patterns in this rock formation result from two distinct modes of weathering.

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

Settled by the Church of Jesus Christ of Latter-day Saints in 1859, this abandoned frontier town has appeared in several films.

This old selenite mine is dotted with tiny crystals that make it shimmer like it's covered in glitter.

Bootleggers ran booze beneath this building before (and after) Route 66 appeared beside it.

A small canyon with petroglyphs and a seasonal waterfall, only a short hike from the remnants of old Route 66.

Rippling sand dunes frozen in the Arizona rock.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

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

Dramatic river bend surrounds a natural red-rocked pedestal.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

In 2008, this Mexico City metro station was the site of an hours-long fight between emo, punk, and goth groups.

Underneath the historic center of Mexico City, the remains of a temple dedicated to the Aztec god of the wind.