Stanpit Marsh is situated on the north side of Christchurch Harbour, just below the confluence of the rivers Avon and Stour. The 65 hectare site has an unusual combination of habitats including salt marsh with creeks and salt pans, reed beds, freshwater marsh, gravel estuarine banks and sandy scrub. Events and activities regularly take place at the Nature Reserve, suitable for children, young people and families. Stanpit Marsh is grazed by New Forest Ponies and this is a key component of management. There are two separate herds: the main herd which permanently lives on site and a seasonal herd, that grazes Priory Marsh and is removed over winter. The ponies, which are semi-wild, are cared for by a grazier.

Ground generally flat but site can get very wet, especially at high tide. Some parts of circular gravel path can be rough due to tidal action. Dykes and ditches are often crossed by raised sleeper bridges. Car park available next to Stanpit Recreation Ground.Dogs must be kept on a lead at all times.