Watergate Bay just outside Newquay. LOADS of rocks stretching all the way down the coast, mainly big rounded boulders. For more streety natural check out Cligger, just on the hill overlooking Perrenporth, its an old tin mine I think, but theres loads of concrete blocks.
Basically the people you want to speak to on here about spots in Cornwall are Bigman, Rich Pearson and Dan Pearce. They will sort you out.
Hope this helps.
Rob