This morbid, delightful curiosity shop offers everything from animal bones to human teeth.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

The world's longest known cave system.

Less a museum than a bizarre fantasy world created by artists and engineers.

The last holdout of a pre-Civil War rebel who took the matter of slavery into his own hands.

America's post-nuclear-attack chambers of Congress.

This red-eyed chrome beast pays homage to the popular modern myth of West Virginia's insectoid monster.

A small storefront museum explores the history and myth of West Virginia's famous urban legend.

One of the largest artillery pieces in the world sits in a Washington D.C. parking lot.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.

Home to items never before seen by the public.

This sprawling museum holds one man's giant collection of real tanks.

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

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

A secretive collection featuring objects that were designed specifically for U.S. intelligence operations.

Elvis's own personal tropical hideaway.

Every day a troupe of pampered water fowl walk the red carpet to their favorite fountain.

The secret city built by the Manhattan Project.

More than five miles of underground passageways.

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

Better known as the "Body Farm," this unique research facility has been studying how human bodies break down since the 1980s.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

The trials and tribulations of marking Poe's grave.