One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

A real flying saucer, contracted by the U.S. Air Force.

You can walk through the first Boeing Air Force One, which famously carried JFK's casket from Dallas back to D.C.

This stuffed pigeon of war had the very serious name "John Silver" until he lost a leg in battle.

Inside houses a vast collection of military aircraft and missiles spanning the ages.

The world's first aircraft factory has been hiding inside an automobile plant for almost 80 years.

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

The twin towers in this Chicago fountain use 50 foot tall video screens to spit on people.

The last living thing to come out of the rubble after 9/11 is now a symbol of hope and resilience.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

The 72-foot giant escaped confinement in a large patch of mulch only to be reburied in the sandy shores of the Potomac River.

The tomb was guarded by soldiers from both sides of the war, and some left their initials carved in the brick.

One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

This modern castle sat empty for decades before a fire inspired its builders to complete its luxury halls.

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

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

The largest land animal skull ever discovered.

A modernist landscape of water and sci-fi concrete.

These unusual rooms on wheels are holdovers from the 1960s.

An astounding collection of medical specimens, including bits of President Lincoln.

Built in 1945, this historic train station has a new lease on life with its baggage area serving as an event space.

Giant acorn-shaped 19th century gazebo from which suburban Washingtonians gazed upon the original "silver" spring.

The childhood home of the Sultan of Swat is just a line drive away from Oriole Park at Camden Yards.

One of the oldest anatomical theaters in the U.S. still in use was once the site of an infamous cadaver riot.