Sioux City () is a city in Woodbury and Plymouth counties in the U.S. state of Iowa. The population was 85,797 in the 2020 census, making it the fourth-most populous city in Iowa. The county seat of Woodbury County, Sioux City is the primary city of the five-county Sioux City metropolitan area, which had 149,940 residents in 2020. Sioux City and the surrounding areas of northwestern Iowa, northeastern Nebraska and southeastern South Dakota are sometimes referred to collectively as Siouxland. Sioux City is located at the navigational head of the Missouri River. The city is home to several cultural points of interest including the Sioux City Public Museum, Sioux City Art Center and Sergeant Floyd Monument, which is a National Historic Landmark. The city is also home to Chris Larsen Park, commonly referred to as "the Riverfront", which includes the Anderson Dance Pavilion, Sergeant Floyd River Museum & Welcome Center and Lewis and Clark Interpretive Center.