Nicknamed "The Triangle" because it is "a distinctive and difficult-to-access triangle" bounded entirely by railroads, Burnside is the smallest of Chicago's community areas. The neighborhood actually "occupies a different physical place from what earlier Chicagoans knew as Burnside." The area was originally known as Stony Island, followed by Burnside Triangle, and it was situated "almost entirely in the community areas of Roseland and Chatham." Only after the 1920 mapping of community areas by University of Chicago sociologists did the area officially become Burnside.