Can highly recommend Beckbrook Farm at Madingley (CC CL listed under Cambridge). This is on the north side of Cambridge (opposite to Addenbrookes unfortunately), but is a little gem. Well kept and feels secure, in a private setting. There are no hookups here, but this is a delightful little oasis tucked in beside the owners woodland, and is easily accessible from the A14/M11 junction. Just follow signs to 'Madingley' and the farm entrance is on the right after half a mile. If you want rural seclusion with easy access, this is it. Hope it helps.