You can take a class, browse the library, or visit the lavish lair of an international men's humor society.

The 30,000-volume library is one of the world's most impressive poetry collections.

This modest post office sits on the site of H.H. Holmes' famous murder castle.

This historic hotel invented the chocolate brownie.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

This abandoned asylum was once a state of the art facility before devolving into one of the most deadly mental institutions in American history.

Once decrepit and slated for demolition, now one of the longest pedestrian bridges in the world.

A particularly creepy abandoned hospital that sparks interest for lovers of the supernatural.

Like Mars, but much closer.

This former maximum-security prison is creepy, sobering, and supposedly haunted.

Once a gas station, this flightless airplane beside the Old Dixie Highway now houses a barbershop.

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

An abandoned town is hidden in Great Smoky Mountains National Park.

This winding road of 318 curves is a must-visit for (careful) motorcycle and sports car enthusiasts.

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

The remains of a failed attempt at medieval nerdery are hidden deep in the woods of Virginia.