The Trent–Severn Waterway is a canal route traversing Southern Ontario cottage country, and a linear National Historic Site of Canada administered by Parks Canada. It was formerly used for industrial and transportation purposes, and is maintained for recreational boating and tourism. The Waterway connects two of the Great Lakes—Ontario and Huron—with an eastern terminus at Trenton and a western terminus at Port Severn. Its major natural waterways include the Trent River, Otonabee River, the Kawartha lakes, Lake Simcoe, Lake Couchiching and the Severn River. It is open for navigation from May until October, while its shore lands and bridges are open year-round.