A farming and light industrial village some 5 miles (8.0 km) east of Béthune and 18 miles (29.0 km) southwest of Lille, at the junction of the D166 and the N41 roads, by the banks of the small river Surgeon.
The marshes of Cambrin are an area of ponds and swamps bordering the communes of Cuinchy and Annequin. They cover 22 hectares and are open to the public. This natural space is managed by the Nature Conservatory Sites of Nord and Pas-de-Calais.
As fenland, it plays a major ecological function for the water for the town and surrounding area and contributes to reducing the pollution of surface water. The marshes, which had formerly been used to pump cooling water to the power station of Violaines, consists of a vast wooded wetland. The place is so attractive that a discovery trail has been created for visitors to enjoy their natural heritage. Many species of birds may be observed along this path.