Canatara Park is Sarnia's largest urban park and the city's best free attraction. A long crescent of clean sand along Lake Huron, a small wooded pond with walking trails, a children's farm, and the Animal Farm petting zoo make it the obvious destination for a family afternoon. The beach itself is wide, gently sloping, and supervised in summer; the water warms up enough to swim by mid-July.
Off-season, the trails around Lake Chipican loop through dune forest that is unusual this far inland; spring and autumn migrations bring genuinely interesting birding. Free parking, no entry fee — both still surprising for a beach this size.