The Cold War-era "underground Pentagon" is a sprawling subterranean hideaway for the Defense Department.

The famous bell was secreted away and hidden in a church in Allentown during the British occupation of Philadelphia.

The Pennsylvania landscape depicted by a quarter mile of mosaics made from used road signs.

A failed piece of Orientalism has become the proud symbol of a community.

This eerily well-preserved coal town was saved from destruction by a Sean Connery movie.

Over 100 concrete munitions bunkers are all that remain of a Pennsylvanian village seized by the US government.

A train station that was abandoned by the coal industry and was later converted into a cocktail bar.

The headquarters of the Fraternitas Rosae Crucis, complete with Rosicrucian pyramids, all in the Pennsylvania woods.

Once the "Eighth Wonder of the World," this iron railroad bridge was decimated by a tornado.

This permanent exhibition celebrates the finest of our heartless automatons both real and fictional.

An abandoned stretch of highway, deteriorating next to the operational one.

Philadelphia boasts one of the best — and most often overlooked — traditional Japanese gardens in North America.

A Museum of Holography frozen in 1974.

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

A haunting statue called "Eternal Silence" has quite the reputation among visitors with active imaginations.

A giant bronze coil of feces is both a tribute to doggie defecation and a reminder to pick it up.

This shop for all your super spy needs hides an educational secret.

Large tower used for simulating radiation of Hiroshima bomb and the tallest object ever relocated.

Mysterious meeting place for UFO hunters near Area 51.

The site of an underground detonation of a megaton nuclear bomb in the middle of the Mojave Desert.

This massive crater in the middle of nowhere was used to train astronauts for moon landings.

If you want to take a peek at Area 51, this is legally as close as you're going to get.

An eatery for UFO seekers on the Extraterrestrial Highway.

Originally built as a promotional giveaway, this suburban house was designed to be an IRL version of the Simpson home.