In reply to Jules King: if they're young, do be ready to protect them over the traverse to the start of the routes if you're doing anything left of Geological Groove. There are a couple of good niches you can belay them to and them have them wait for you to traverse over to yourself.
In reply to Jules King:
I think the approaches to Chair Ladder and the tidal base are not really suitable for younger kids. Plus the routes are all multi pitch.
I would second Bosigran, easy walk in to Alison Rib area and some nice single and multi pitch V Diffs with good feeling of exposure. If you fancy a longer walk in, the Red Slab area at the end has got some nice easier routes and more of a cliff climbing feel.
In reply to Jules King: There is a very easy slab at the top of pinnacle buttress at Chair Ladder which is easy to get to - its only Mod/Diff - ideal for absolute beginners - not much else at CL without scary descents.
Working clockwise from the southeast. Certainly not exclusive and please take with a pinch of salt as I'm not a frightened 5 year old, but these are all good and could be suitable.
Trewavas (easy access, lots at all grades) St Loy (almost the perfect crag, but not much very east stuff) Porthguarnon East (very good tiered crag, lots away from the sea, brambly approach) Penberth (very mellow short pitches, quite close to sea but a good bet. Lots of easy stuff) Logan Rock (amazing headland with lots of stuff high above the sea. Quite lichenous and few recorded easy routes, but plenty of 'climb anywhere' variety. Amazing cool place, ll feel like an adventure just going there - recommended) Pednvounder (not much recorded easy stuff, but it does exist -nudist beach though) Chair Ladder Ash Can Gully (Cave Route HS is good fun & nowhere near the sea. Possibly scrambly approach?) Carn Boel (I took my very inexperienced at the time girlfriend to do Longships Ridge. Small step down on the approach and a bit of exposure, but the best single pitch diff in Penwith imho and with a proper sea cliff feel. Miles above the sea, but exposed) Sennen Obviously John Wayne Memorial Crag (can't recall exactly, but I think this is non-tidal. Short easy pitches, nothing that great, but quiet and good outlook) Rosemergy Ridge (plenty of easy climb anywhere stuff. Miles from the sea, beautiful, recommended) Brandy's Slabs (awkward approach, suitable once you're there) Bosigran Alison Rib area (A good bet)