Geography of Illinois is the study of the physical features and human-made structures of the state of Illinois. The state is located in the Midwestern United States and is bordered by Wisconsin to the north, Iowa to the west, Missouri to the south, and Kentucky and Indiana to the east. The state is divided into four distinct geographic regions: the Central Plains, the Great Lakes Plain, the Mississippi Embayment, and the Interior Lowlands. The Central Plains region is characterized by flat, rolling terrain and is home to the majority of the state's population. The Great Lakes Plain is located in the northern part of the state and is home to the Great Lakes. The Mississippi Embayment is located in the southern part of the state and is home to the Mississippi River. The Interior Lowlands region is located in the western part of the state and is characterized by rolling hills and valleys.