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

Dramatic river bend surrounds a natural red-rocked pedestal.

A mysterious monument meant to be a guide into "an Age of Reason" was destroyed after an apparent bombing.

A bizarre roadside attraction and the first instance of miniature golf in the world.

The highest point in Tennessee, Clingmans Dome bears witness to the ravages of one type of insect.

These unusual rooms on wheels are holdovers from the 1960s.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

Elvis's own personal tropical hideaway.

A recreation of the doomed ocean liner in the middle of the Smoky Mountains.

The hotel where Martin Luther King Jr. was shot is now a museum dedicated to his work.

Home to drunken tower-climbing goats... seriously.

The bullet-riddled wall from the St. Valentine's Day Massacre, bloodstains enhanced for your viewing pleasure.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

Walk in the footsteps of the gods and straddle two tectonic plates.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

Medicinal spa created with the discharge from a geothermal energy plant.

The world's longest known cave system.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

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

Lady Liberty's first beacon of enlightenment is now displayed in a museum near the statue.

One of only two commuter aerial tramways in the United States.