A Bibliophile's Dream.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

The iconic D.C. restaurant where the Cuban Missile Crisis was negotiated, now a Walgreens.

This unique museum cafeteria showcases the history and regional diversity of African American cuisine.

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

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

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

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

A museum cafe showcases Native American dishes and indigenous ingredients from across the Western Hemisphere.

Was there a small "backpack nuke" hidden in the attic? JFK apparently thought so.

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

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

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

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

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

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

Home to a vast and influential collection of Shakespeareana.

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

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

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

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

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

The institution is sitting on a goldmine of 21,000 paints, varnishes, pigments, and primers preserved for posterity.

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