sentences:  The Paglesham Reach is also significant for its native oysters.The River Roach flows across the Rochford Basin, a nearly circular topographical basin, with Rochford near its centre.To the south is the River Thames, and to the north, the River Crouch, but the basin is surrounded on three sides by the low hills of Canewdon, Ashingdon, Hockley, Eastwood, Westcliff-on-Sea, Prittlewell and Southend-on-Sea.