A devilishly named gorge that was a sign of salvation for many pioneers.

A monument to the egos of two railroad magnates that fell into decline along with their careers.

Miraculous tree that seems to sprout out of solid rock.

A popular rock that acted as a waymarker for American pioneers.

Long before guestbooks and hotels, frontier travelers signed their names on this rock face.

This rustic old building is said to be the most photographed barn in America.

This prison-turned-museum is a remnant of the Old West's grizzly, violent past.

A century-old cabin off of Highway 30 touts an unusual construction material: dinosaur bones.

One of the smallest towns in the United States.

Devilish landscape, once cinema home to giant alien bugs, now derelict roadside attraction.

This Yellowstone geyser may not shoot as high as the nearby Old Faithful, but it erupts for considerably longer.

An architect's childhood fantasy treehouse made real.

Native Americans built this circle of stones, which was used to predict astronomical events.

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

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

A beautiful geyser under environmental threat.

The first declared National Monument in the United States.

Single runway interrupted by a busy road that cuts across its middle.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

The nuns here cultivate silk to weave some of the finest scarves in the world.

One of Ireland's most infamous prisons for rebels including men, women and children.

One part local history, 99 parts gruesome haunted house.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

Eighty million natural history specimens call this gargantuan museum home.