There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

Daredevil repair workers can worm their way out the access hatch, loop ropes over the apex and rappel down the monument.

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

The U.S. Fish Commission’s effort to mass produce carp.

A tiny monument to the unsuccessful attempt by Thomas Jefferson to place the prime meridian in Washington.

Look closely and you’ll notice that the color changes a third of the way up the tower.

This dramatic rail curve was once the target of a failed Nazi attack.

An abandoned stretch of highway, deteriorating next to the operational one.

One of the world's tallest Ferris wheels takes visitors high above Las Vegas in a spinning party room.

A giant open-air sculpture made of over 200 full-sized boats.

Stepping away from the glitz of mobsters and casinos to learn about the other history of Vegas.

This incredible collection of vintage pinball machines can be played at 25 cents a pop.

This former lieutenant governor's home is brimming with curiosities.

The Kirkland Monument remembers a selfless Civil War hero who braved the battlefield to give water to his dying enemies.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

This museum devoted to the gothic author holds such interesting ephemera as his socks and walking stick.

Collecting 700 years of mechanical death-dealing, the NRA's sprawling gun museum is a revealing testament to the American obsession with armament.

A place of great reverence for Trekkies everywhere, a hero's future birthplace.

A pop-culture attraction outside of Dyersville, Iowa, hits a home run.

The World's Largest Bull.

This simple home was the beginning of a long journey for the iconic Western film star.

Roaming bison and a spectacular view at the highest point in Nebraska.

An experimental, automotive replica of Stonehenge.

Even in death, he's still your huckleberry.