In reply to Dribble223:
I used to live in Warwick and used the uni wall all the time. The only other place I know of is the wall at the sports centre (St Nicholas Park) in Warwick. Its only a two small walls in the corner of the sports hall but it will definitely be quiet. I think the Warwick Mountaineering Club use it too.
Other than that, you're looking at the walls in Birmingham or Northampton wall.