Portland addresses, since the early 1930s, have been divided into five different categories: North, Northeast, Northwest, Southeast, and Southwest. The ordinal categories are determined by using Burnside Street as the North-South dividing axis, and the Willamette River as the East-West dividing axis. North Portland doesn't easily fit on these axes, because the Willamette takes a sharp turn to the West before it meets the Columbia, creating the peninsula that is North Portland. Because the city is otherwise quartered in this applied geography, North Portland is sometimes referred to as "the Fifth Quadrant", giving the system as a whole the nickname, "the Five Quadrants".
A pub in North Portland is named The Fifth Quadrant in honor of the area's nickname.