Hi Richard
I'm from Northampton and have just looked in northampton Yellow Pages. Cogenhoe(pronounced cookno)Mill Caravan Site(01604 890579, Mill marina and caravan park Trapston(01832 732850, Overstone Lake caravan park (01604 645255), Riverview park cogenhoe 01604 891411. I dont know any of these sites so i cant comment. Give them a ring and ask for a broucher. avoid Billing aquadrome like the plague its dreadful.