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

An abandoned observatory in the middle of the Illinois prairie.

This nondescript tunnel has been featured in a number of iconic movies, from “Roger Rabbit” to “Back to the Future.”

Inside the Wayne County airport is an amazing collection of lights and sounds.

A spectacular remnant of an Adler and Sullivan masterpiece that was destroyed in 1972.

A hot dog stand where the heads are just as hot as the dogs.

One of the largest pieces of scientific equipment ever carried on a NASA space shuttle sits in a Chicago alley.

The final resting place of up to 6,000 Confederate soldiers, the largest mass grave in the Western Hemisphere.

A 315-foot spire jutting out from the Blue Ridge Mountains makes for breathtaking views.

The superstar of Cold War nuclear bunkers has been featured in countless films but is now barely operational.

The lighthouse central to the 1980s horror classic "The Fog" is, in fact, located in one of the foggiest areas of the Pacific Coast.

The beauty of urban decay, hiding some dark secrets.

If astronomy had a ghost, it would look like this observatory.

These cabins mark the site where our 11th president was born (probably).

An eccentric priest's tribute to George Washington, this chapel tells the story of the American Revolution.

The oldest surviving presidential residence in the United States.

Alexander Hamilton’s creation caused quite a bit of controversy.

North America's oldest quarantine facility was built in response to Philadelphia's 1793 yellow fever outbreak.

Current docking place of the SS United States, the fastest transatlantic ocean liner.

Erected in 1697 this Philadelphia bridge is the oldest surviving roadway bridge and perhaps the oldest stone bridge in the United States.

This elaborate towering structure was once famed for its revolutionary height.

This little-known Revolutionary War fort is supposedly haunted by the ghosts of its past.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."