Lake Charles is a brackish body of water located within the estuary of the Calcasieu River in Southwest Louisiana, United States. It is situated almost entirely within the Lake Charles city limits. The Calcasieu Ship Channel flows along the western side for large ships to pass and is the western boundary of the city limits. The I-10 Calcasieu River Bridge crosses at the extreme northwestern edge of the lake and river and connects the city of Lake Charles and the city of Westlake.