A memorial dedicated to a highly decorated Marine and Korean War veteran, who also happened to be a horse.

Once home to seven different roller coasters, Glen Echo has undergone many transformations since its founding in 1891.

The bridge's highly-contested plaque (once again) honors Confederate President Jefferson Davis.

First built around 1848, this bridge was destroyed by arson, but original timbers are included in the replacement.

This Maryland farm is known for its amazing corn mazes and its 30-foot junkbots.

The headquarters of Korea’s provisional government later became the site of a prominent statesman's assassination.

A lightship turned museum, outfitted with artifacts from the vessel's past as part of the U.S. Lighthouse Service.

A British Commonwealth cemetery in the heart of Milan, with 421 allied soldiers died during World War II.

This environmental engineering marvel keeps salt water from the Elizabeth River.

Get up close and personal at this Fresnel Lens.

Honorable ranks graduating from the prestigious Army War College work hard to maintain their high standards of honor and erase those who don't.

The tunnel under the Capitol Building where Congress takes out its trash.

The innocent intentions of this monument are somewhat lost in the sculpture's muscled imagery.

The grand marble structure next to the White House is Andrew Carnegie's temple to Pan-American diplomacy.

Disks are rolled out onto the south lawn to absorb the impact of Marine One's wheels like giant coffee coasters.

This statue of one of baseball’s greatest pitchers looks like something out of a sci-fi horror movie.

An 18-mile-long tunnel for sewage waste will soon wind within the bowels of Washington, D.C.

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

A portal into the bricked up canal that runs through the heart of Washington D.C.

Amid the sprawling Defense Intelligence Agency Headquarters is one of Washington's least accessible museums.

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

When it comes to handsignals (and colonialism) rock always beats scissors.

Before Nixon, "watergate" meant canals.

This unacceptably tall building was the real reason for Washington, D.C.'s skyscraper ban.