High Quality Content by WIKIPEDIA articles! 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 (Drainage Canal), thence to Union Bay, and Lake Washington. Drainage Canal is one of three or four areas of open water connected with Lake Washington around Union Bay Marsh. The canal extends from NE 45th Street, between the driving range and IMA Sports Field 1, south to the bay, ending southeast of the Husky Ballpark baseball grandstand (northeast of the IMA Building). The Drainage Canal that carries Ravenna Creek past UBNA to Union Bay is locally sometimes called University Slough, though that is...