In reply to minty1984:
Maybe further away, but I had a successful visit to Sand Point, just north of Weston Super Mare, with a couple or junior aged children. Easy access, they liked the venue and there are loads of Mods and Diffs for them to go at. Set ups were ok. Routes short, so not intimidating and meant plenty of turns. No one else there all day, so no problem setting up a few top ropes and leaving them in place while they switched between climbs. Fair amount of low level 'child' bouldering on some of the lumps of rock at the base of the descent ramp too...
Enjoy the day,
Jim