Burlington is a city and the county seat of Des Moines County, Iowa, United States. The population was 25,663 in the 2010 census, a decline from the 26,839 population in the 2000 census. Burlington is the center of a micropolitan area including West Burlington, Iowa, and Middletown, Iowa, and Gulfport, Illinois. Burlington is the home of Snake Alley, once labelled the crookedest alley in the world.