This church in Pittsburgh is home to the largest collection of religious relics in North America.

The only way to see Pittsburgh is from the top of this lookout point, just like the ancient members of the native peoples did.

The residents of the Neighborhood of Make-Believe live without much fanfare within the Pittsburgh Children's Museum.

A dramatic, 360-degree recreation of Pickett's Charge in the Civil War.

The home of possibly the least-loved U.S. president stands as a sort of unpopular Monticello.

This extraordinary Depression-era expenditure was modeled after a postcard of a Mediterranean hotel.

Less a museum than a bizarre fantasy world created by artists and engineers.

This museum on a college campus pays tribute to the Arctic and to two explorer alumni.

This handsome giant is said to mark the birthplace of the mythical woodsman and even had a cameo in a Stephen King novel.

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

The preamble to the U.S. Constitution written entirely from vanity license plates hangs in the Smithsonian museum.

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

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

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

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

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

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

This sandwich shop has a century-old elevator behind a sheet of plexiglass.

The "lovely red Vega" of the legendary record-settling pilot.

The national park was once a plantation estate.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.