Montreal's largest park occupies a peninsula in Pierrefonds-Roxboro where the Rivière des Prairies meets Lake of Two Mountains, with water bordering three-quarters of its roughly 330 hectares. Now part of the Grand parc de l'Ouest, Cap-Saint-Jacques packs in an unusual amount of countryside for a city park: an ecological farm run by the nonprofit D-Trois-Pierres, which supports work reintegration, keeps cows, horses, and chickens, and sells its organic vegetables, eggs, honey, and maple syrup at an on-site general store.

A natural sand beach sits in a sheltered, motor-free bay facing the Oka hills, well suited to swimming, kayaking, and paddleboarding. An extensive trail network winds through woods and meadows for hiking in summer and cross-country skiing in winter, with picnic tables scattered from the farm to the waterfront.