A large family park in Northwood, Christchurch, reached from Johns Road. Its name comes from concrete-filled wool-sack groynes placed in the Ōtukaikino Creek in the 1930s for flood protection. The park has walking tracks, including the Ōtukaikino Track, the Island River Loop and the Waimairi Walkway, plus picnic areas and free barbecues.
Children can use several playgrounds, with a flying fox, bridge, see-saw, slides and swings, and a naturally inspired playground near the boatshed. A large dog exercise park is fenced, and dogs must be leashed across most of the park. Weekend boat hire on the recreation lake includes pedal boats, aqua bikes and canoes, and the website gives opening from 10.30am to 4pm. There are white (1.9 km) and yellow (2.6 km) orienteering courses. A map costs $4 as at 2026 from the Rosebank Cafe near the entrance. Anglers can fish the lakes all year, and streams are closed to fishing from April to October. Children under 12 need no licence.