The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

The Magic House provides a beautiful and creative environment for curious youngsters to get their knowledge on.

This huge dam across the Colorado River caused an armed standoff between two U.S. states.

This former Indiana quarry has been transformed into a park and SCUBA site where divers can explore the drowned mining equipment.

This hidden stream beneath Indianapolis makes an appearance in the best-selling novel "Underground Airlines."

Ornate limestone building now filled with geologic specimens, and more.

Huge abstract sculptures of the Puerto Rican Flag.

A military museum and library dedicated to the citizen soldier.

First known as the "Sample House," this construction mash-up was meant to be a living catalogue of building styles.

This surprising gem is a world-class archeological museum hidden at the University of Chicago.

This historic-shipwreck-cum-diving-spot can still be seen poking its boiler out of the Lake Michigan waters that claimed it.

Quirky water tower advertises the long-gone Brooks Tomato Products Co.

Tour the luxe "glass cage" that inspired and unnerved the architecture world upon its debut.

The iconic Chicago sculpture hides a beautiful and easily overlooked plaque on the backside.

A beloved Chicago music venue offering cold beer and lots of “Friendly."

This grave in a ghost town cemetery marks the death of a witch on a day that never happened.

The final resting place of the world's first nuclear reactor.

The face of a woman pushes its way through the earth.

These pretty kitties killed and ate as many as 135 railway workers.

Beloved bar home to musicians of all eras and reputations.

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