Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

Home to items never before seen by the public.

A small and somewhat hidden memorial to 68 local veterans of the Vietnam War.

Washington's iconic carousel has a nice piece of Civil Rights history.

Largest Roman Catholic church in North America.

This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.

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

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

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

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

A haunting tribute to pioneering photographer Clover Adams.

The sculptor was instructed to add “stallion attributes” to the general's bronze mare.

A bas relief commemorates the "Nuns of the Battlefield" who cared for soldiers on both sides of the conflict.

The national park was once a plantation estate.

There's a crumbling old mansion inside the Smithsonian National Zoo.

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

At 207 feet, one of the world's longest continuous escalators.

A building shaped like the Army Corps of Engineers logo, because why not?

A girls' boarding school inspired by the Chicago World's Fair, once abandoned, now restored to strange and scenic glory.

The tallest The Church of Jesus Christ of Latter-day Saints temple in the world soars above the Beltway.

The longest escalator in the Western Hemisphere takes over three minutes to ride down.

The story behind the mysterious symbol painted in front of the historic university's famous Rotunda.

FDR's Art Deco hospital tower was hopelessly inefficient.