In reply to andybuckley:
Yeah, the walk-in to Lower Cove is really pretty flat. With a 5 year-old you'll be walking at least an hour and a half if you carry him and more if you don't... First Corner is probably the best one for treating like an outdoor climbing wall – big holds all the way, lots of scope to move about left or right, but it's taller than 10m, more like double that I think. It's easy enough to walk up the gully and on top to rig a top rope, I've done it successfully with beginners before, no problem at all. Far Left Buttress right next to First Corner also has a big load of nice grippy flakes (the main line through it, 'New Decayed', has nice big clambering moves lower down and decent flakes further up). There's similar scope for toproping on top of 3rd corner, and for shorter stuff to do it part way up the gully. Take headtorches (and helmets) and go explore the cave - there's also the passage that goes through and under and comes out near the top.
Hen: shorter walk-in (20 mins for an adult) but much more of an uphill, and it's not like there's a decent path to the rock at the top – you just push off the path up over steeper moorland. Once there it's certainly easy enough to walk to get the top of most lines for rigging top-ropes. Catches the wind pretty hard up there, so worth checking the forecast!
I've seen top-roping parties at Spellack, on the Forest View Buttress. It's a great path most of the way, just uphill approaching the buttress itself. Short routes (15m?).
Annalong Buttress is a really nice and quiet suntrap when the sun's out. Easy to rig for beginners, nice lines, lovely place to picnic, and because it's high up on the valley side you get a nice mountainous feel being there as well. It's a bit of a slog of a walk from Bloody Bridge carpark mind you – you'd have to allow a couple of hours with a small kid, so perhaps plan to break up the day and have a picnic in the abandoned mine on the way up, and take lots of snacks to keep the energy up enough for the return. Again, more than 10 metres – think they're about 25 m there.
Bernagh slabs – I think the hike's not gonna be too bad, it's a good path the whole way but it makes quite a bit of ascent over the distance, and it takes adults over an hour. I can't think that there's a straightforward way to rig a top-rope there though, I mean unless you're happy to lead up a distance and then rig an anchor and lower off it, then go back up a strip it later and perhaps downclimb. The first 10 metres of, say, Grand Central, or Hypothesis, are straightforward enough to solo/downclimb, but they're not replete with protection anyway at that stage – they follow grooves in slabs- so it's not exactly clear that they're going to be great for rigging a toprope once you've gone up a bit.
Sorry if that comes across as a bit of a wet blanket, just thinking about all your variables. I've had success at Lower Cove and Annalong, so happy to encourage you to consider them. I'm wracking my brain to think of other decent options. (I figure Percy Byshe is a bit uninspiring but ymmv).
