DC is divided into four quadrants with the Capitol Building’s rotunda as the center. The dividing streets are North Capitol, East Capitol, South Capitol and the National Mall. Therefore, the Mall is basically split down the middle: The Smithsonian Castle, Air and Space Museum and Lincoln Memorial are in southwest DC, while the Natural History Museum and American History Museum are in northwest DC.
Street and number addresses start out at the Capitol so there are many identical addresses. That’s why it’s VERY important to note the quadrant, otherwise, you could be looking for a building on K Street SE, for example, when you are really meant to be on K Street NE.
Streets running north and south are numbered (1st, 2nd, etc.) and streets running east-west are letters (interestingly, there’s no J).
The quadrants aren’t identical sizes and they never were. At one time it was an almost perfect square but now—see that big chunk out of southwest?—that’s Arlington and Alexandria, which the district eventually gave back to Virginia.
Northwest is the largest of the quadrants, covering over a third of the city. Its neighborhoods include Federal Triangle, Dupont Circle, Foggy Bottom, Adams Morgan and Georgetown, among others. This quadrant is typically what people think of when they think “DC.”
Southwest is the smallest quadrant and is really just a sliver of the city. Southwest is dominated by the waterfront area as well as the Bolling Air Force Base and Anacostia Naval Station.
Northeast’s neighborhoods include Pleasant Hill, Fort Totten and much of Capitol Hill, among others. The National Arboretum and Gallaudet University (a well-known school for the deaf) are also found here.
Southeast is bisected by the Anacostia River and contains the Library of Congress, Eastern Market, Nationals Stadium and the newly revamped Navy Yard.