At the confluence of the Thames River and Trout Creek, St. Marys, known as The Stone Town, features a former limestone quarry that is now Canada's largest outdoor swimming pool. The limestone from the quarry was used to construct many of the town's fine 19th-century buildings. The Grand Trunk Trail Walkway is a conversion of part of the disused track of the railway into a picturesque public walkway spanning the Thames River. Learn More...