What was once a summer home next to a waterfall has now become littered with graffiti and children in swimsuits.

Once the smallest park in the national system.

Claims to be the "World's Highest Hill."

A half-size replica of the World Trade Center towers above Tulsa.

This highway overpass was named after the tragic disappearance of a young mother who got mixed up with the wrong people.

One of the largest Masonic temples in the world, created at the height of the oil boom in ostentatious style.

Songwriter Leon Russell transformed this church into a recording studio used by many legendary musicians.

This abandoned, windowless concrete block is one of the strangest buildings in Tulsa.

One of the best examples of Art Deco architecture in the United States.

An old spiral fire escape dangles above a public courtyard in Midtown Oklahoma City.

A peculiar forest that was handcrafted for government experiments.

Nature's biggest mammal swims in landlocked Oklahoma.

Tucked away on an empty wooded lot in suburban Oklahoma City lie the remnants of an abandoned circus camp.

A whimsical tower with a spiral staircase, inspired by the Space Age and the Möbius strip.

Travel through the hidden underbelly of the city in colorful tunnels filled with art and history exhibits.

This former tuberculosis treatment facility now stands at the center of a public park.

Once home to more than 50 displays of freshwater fish.

The headquarters of a pioneering cast iron and cast aluminum cookware company is in ruins, but still standing.

The site of the worst mining disaster in Ohio's history.

Now in disrepair, this 19th century station was a stop on of the famed B&O Railroad.

A suspended garden, now gone, once hung in the middle of this abandoned church.

The tragic reality of a town riddled with rumors of haunts, chemical spills, and serial killers.

An abandoned relic of the city's failed experiment with below ground transit.

Train fans from all over flock to this railroad viewing park where three lines converge.