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

An obscure federal monument honors the French diplomat who served as Ambassador to the U.S. during WWI.

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

The bank that helped fund the Mexican-American War and the purchase of Alaska met its downfall after helping Augusto Pinochet launder money.

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

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

A much-maligned monument to teetotalism.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

An unassuming, powerful monument north of the U.S. Capitol bears witness to the resilience of Japanese Americans during a time of grave injustice.

A Spiritualist house of worship where believers communicate with the dead in the spirit world.

The privately owned cemetery that holds room for Washington's finest when they step down from life.

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

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

A super-sized promotional trick that is now a D.C. landmark.

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

Light bulbs, scrap wood, and tinfoil comprise this homemade throne of the gods.

The house where John Wilkes Booth conspired with his co-conspirators.

Largest Roman Catholic church in North America.

America's Most Wanted's set resides in this tribute to the history of crime and punishment.

A tiny piece of the Moon is embedded in this stained glass masterpiece.