This lush forest valley was once mined for lumber to the extent that it was once nicknamed "The Pennsylvania Desert."

"Dark Sky Park" is heaven on Earth for astronomers, one of the rare U.S. locations with no artificial light pollution.

Memorializing an American tragedy of massive proportions.

This museum is housed in an unassuming building that witnessed one of the most daring feats of satire in modern history.

A much-maligned monument to teetotalism.

Before founding the American Red Cross, Clara Barton had a tremendous humanitarian impact by locating thousands of missing soldiers.

Natural rock water slides hidden in the remote forests of northern Idaho.

The largest outdoor art gallery in the Northwest United States.

A creek tumbles over a series of step-like rocks to create this scenic water feature.

A basement full of treasures lies beneath this inn that has worn many hats throughout its 140+ years.

Rusty pieces of metal jutting out of a breakwater are all that's visible of the 12,500-ton ocean liner that capsized just off the beach.

The internal railway of one of the biggest steel plants in America has been transformed into a linear park with unique industrial views.

It's safe—and permitted—to walk across these twin natural sandstone arches.

A century-old church is now a space museum with a treasure trove of Soviet space items.

This large artificial waterfall in Washington state was merely an incidental byproduct of a technological megaproject.

Twisted trees shaped by coastal winds make this woodland look like something from a spooky story.

This wildlife trust is dedicated to orphaned elephant rescue and conservation.

This massive Roman Catholic rosary is composed entirely of wood.

One of almost 200 confirmed impact craters in the entire world, untouched for tens of millions of years.

Approximately 50,000 gallons of water gush from these springs, creating the Metolius River.

In Rickwood Caverns, visitors can travel hundreds of feet underground and see beautiful formations unique to the region.

A conservation sanctuary for rescued koalas, some of which were saved from devastating Australian bushfires.

This spooky road cut through a mound of ancient coral might be haunted by a witch.

The longest skywalk in Taiwan.