The city is divided into four quadrants, North East (NE), North West (NW), South East (SE), and South West (SW), with the US Capitol being the focal point of each quadrant. This is very important because the streets are number the same in each quadrant, so you don’t want to end up at 1st and C ST. SE, on the House side when you were supposed to be at 1st and C ST. NE on the Senate side.
If you are using GPS be sure to include the quadrant. For example, if you need directions to Cannon House Office Building, this is how the address should read: 27 Independence Ave. SE, Washington, DC 20003.