An eerie, abandoned military base engulfed by nature and graffiti is now home to a local park.

This elaborate towering structure was once famed for its revolutionary height.

This meticulously extracted nervous system allegedly came from a 19th-century custodian who donated her body to science.

Yo, Adrian!

A clone-tree in Washington Square Park sprung from seeds that went to the Moon and back.

A layered tribute to the work of mosaicist Isaiah Zagar.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

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

An amazing example of early-20th-century architecture, this church features marble transported from Utah.

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.

A line of blue paint marks the route of the inaugural parade.

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

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

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

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

Before Nixon, "watergate" meant canals.

Art deco landmark on the outskirts of Washington, D.C.

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

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

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

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

An overlooked oasis of quiet on the grounds of Washington's monumental basilica.

Decades before the scandal, this staircase on the river was a literal "water gate."