The Union Bay Natural Area (UBNA) in Seattle, Washington, also known as Union Bay Marsh, is the restored remainder of the filled former Union Bay and Union Bay Marsh after University Village Shopping Center, the University of Washington (UW) athletic facilities, buildings, and main parking area (E1). It is located at the east end of the main UW campus, south of NE 45th Street and west of Laurelhurst. Ravenna Creek is connected to University Slough, thence to Union Bay, and Lake Washington.