Built in 1815, the stabilized ruins of the grist mill and sawmill are now gated, but interpretive displays on the features and functions of the mill preserve its history.

A celebrity from the late Cretaceous period.

The word "Watergate" will forever be associated with the infamous scandal in 1972, but this fountain is famous in its own right.

An echo chamber with a waterfall wrapped around its base at the Embassy of Canada in Washington, D.C.

Railroad officials in the early 1900s sought to spare travelers the sight of Roman soldiers’ private parts.

A tribute to the pop culture icon overlooks this Washington D.C. intersection.

On the Fourth of July this area will transform into a Pompeii-like storm of falling embers and ash.

This statue of the "father of television" stands prominently in the United States Capitol.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

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

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."

The U.S. Navy’s preposterously detailed mini battleship took 77,000 hours to complete.

Part of a WWII submarine is lurking outside the Washington Navy Yard parking lot.

Need a hardcopy of the 50-title Code of Federal Regulations? This is the place.

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

Also known as the Founding Church of Scientology.

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

A hidden passageway now marks the site of an assassination attempt on Ronald Reagan that some say broke a 140-year-old curse.

One of the most influential presidents in U.S. history wanted only this plain, elegant monument as his lasting memorial.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

"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!”

An overlooked memorial honoring the local Washington residents who died in World War I.

Behind an abandoned storefront is an example of pioneering 1930s gas station architecture.

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