The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

A bas relief commemorates the "Nuns of the Battlefield" who cared for soldiers on both sides of the conflict.

Before Metro, Washington had a robust streetcar network—and you see the remains of this infrastructure if you know where to look.

Washington's top-secret Cold War-era doomsday communications tower is located in a small neighborhood park.

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.

An old abandoned pharmacy building in Texas is brimming with collectibles and images of the little tuxedoed pooch.

A historic ruin just 20 feet away from a busy highway onramp.

A blank headstone topped with a pile of pennies marks the final resting place of the infamous assassin.

Hidden behind Lincoln's head is a 70-foot-long chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

Rusting away on the edge of New Jersey are the remains of a Cold War missile launch site.

This sword isn't waiting for a king to pull it out. It was placed there by a saint.

The great Italian Renaissance painter was laid to rest here in the Chapel of Saint-Hubert.

Four bald cypress trees in Lafayette Square, across from the White House, mark the southern edge of a 100,000 year old cypress swamp.

Enormous piles of historically significant stones, dumped by Congress in a forest, and abandoned for 60 years.

This ceremonial mound is one of the first officially recognized Native American historical sites in North Carolina.

The second largest in the world, this massive underground void has its own subway.

This museum dedicated to an oft-overlooked support industry features a surprisingly moving brass diorama of a man being saved from a sinking car.

Tracks near this Texas nature site were once thought to support the Creationist belief that man and dino coexisted.

Ruins of an American Civil War iron forge still survive today.

Eight rare Corvettes are swallowed up by a sinkhole in Kentucky's National Corvette Museum.

The grave of the iconic Kentucky Fried Chicken mascot features a bust of the man behind the goatee.

This racially troublesome eatery thought a new coat of paint could erase its offensive connotations.

The remains of an idyllic small town built for the film 'Big Fish' still stand around a rundown main street.