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

A portal into the bricked up canal that runs through the heart of Washington D.C.

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

This restaurant has been a haven for D.C.'s LGBTQ community since the 1950s.

The early data processor factory founded in Washington for the 1890 U.S. Census went on to become IBM.

A diminutive plaque recalls the treetop sniper who almost killed Abe Lincoln.

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

Home to a vast and influential collection of Shakespeareana.

D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

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

A rotating cast of guys and dolls in front of a Washington, D.C. building.

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

A three-story tower of books about Abraham Lincoln is one of the more unusual monuments to the president.

One of the last remaining World War II Victory Gardens in the U.S. is quietly growing across from Fenway Park.

One of the now-less-hidden floral gems of the "Emerald Necklace."

Radical Bookstore and Community Space.

This sprawling bookstore spans four floors and has more than a million books in stock.

This small Catskills village has six independent bookstores and more bookshops than restaurants.

Eulogizing an unknown man's unusual demise.

This hunter-gatherer architecture is believed to be the oldest religious complex known.

A bunker "with enough U.S. currency to replenish the cash supply east of the Mississippi" in the event of nuclear war now protects nitrate film.

Inat Kuća, or "House of Spite," is more than just an oddly named restaurant.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

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