River pirates, murderous bandits, and serial killers used this Illinois cave as their debauched hideout.

This replica of an 8th century burial ship actually sailed to Norway before returning home to Minnesota.

A mapping error in the 19th century made loggers think this section of the forest was underwater.

This dig site outside D.C. is known for its exceptionally high density of baby dinosaur fossils and dinosaur eggs.

A plaque commemorates the spot in the Oregon woods where the first-ever Geocache was hidden.

The multinational Burger King chain is banned from operating within 20 miles of a family restaurant filed under the same name.

This large midwestern cavern features impressive rock formations and an underground waterfall.

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

Collecting 700 years of mechanical death-dealing, the NRA's sprawling gun museum is a revealing testament to the American obsession with armament.

A miraculous natural phenomenon known as "the spring that breathes."

Robots, lasers, and whoopee cushions, oh my!

A bizarre house filled with an astounding array of collections.

The world's longest known cave system.

Prehistoric animals decorate this popular outdoor park.

The United States Capitol's former columns still stand.

A place of great reverence for Trekkies everywhere, a hero's future birthplace.

14th century Norse artifacts in Northwestern Minnesota could have proved a Viking landing before Columbus.

Small-town museum dedicated to outer space ... and bicycles.