In reply to Mowglee:
Hi. There's not many campsites that are quiet and cheap to stay near ansteys itself. But you might like to look around Stoke Gabriel which would be 20-30mins or so drive around the ring road to get there(dependent on time, traffic and the bypass works). Nice place, near the river, and a little bit further from the main grock hoards. If it's been raining recently and you want to do stuff on empire wall, it may be seeping.