The history of Fort Willow is closely linked with that of the Nine Mile Portage, a former transportation route between Lake Simcoe and Georgian Bay. The Fort was built during the War of 1812 as a supply depot for the British garrison at Michilackinac Island, near modern-day Sault Ste. Marie.
To get to Fort Willow, take County Rd. 90 to Grenfel Rd. and travel 5 km north to the parking lot on the left. An alternate route is George Johnston Rd. off either County Rd. 90 from the south or Hwy 26 from the north, then go west on Portage Trail for 3 km. The route is well signed. You can access the Trans Canada / Ganaraska / North Simcoe Rail Trail by going down the stairs at the back of the Fort.