This alley in downtown Chicago held the bodies of over 600 people after the fateful Iroquois Theatre fire.

A century-old network of freight tunnels underneath the city's historic business district.

Home to a protest movement, a bombing, and a dramatic change in labor history.

Macabre astrological automaton clock dating to the late 1400s.

Before becoming a public park, this spot was a shell midden, a fort, and an amusement park.

An abandoned underground bunker not far from downtown New Orleans.

The site of the one of the most deadly train wrecks in American history.

An abandoned coal mine reached by a steep hike.

Art Deco urban decay at this historical building.

This abandoned cemetery has a dark past of bodies buried over bodies.

The oldest brick house in the state of Ohio.

Conjoined twins Daisy and Violet Hilton were stars of the vaudeville circuit.

South Carolina's last remaining slavery auction house is now a museum devoted to its own tragic history.

The tallest monument in a historic New Orleans cemetery was prompted by romance and dash of pettiness.

Visitors flock to see this church tower's unintended feature: It happens to resemble a giant chicken from multiple points of view.

This Czar-funded, onion-domed, lavishly muraled Orthodox Church played a starring role in "The Deer Hunter."

This steamer is known as "The ship that built Cleveland."

An elegant sandstone stairway built by the WPA still connects two neighborhoods in Akron.