There was just time enough to ponder the folly of involving the whole family in hearty adventures before I miraculously found a foothold on the slippery rock.
The vertiginous scramble in search of St Mary's Well was just part of a week of outdoor fun on the Lleyn Peninsular on the very western edge of North Wales.
The plan was to forget computer-games, TV and packaged entertainment and drag our children (six of them from two families, plus a dog and a German exchange student) kicking and screaming into the fresh air.
This is how the week panned out:
Sunday 26 July:
Arrive in Aberdaron after long drive through driving rain. Booked into a farm campsite on high windswept field. "You're a braver man than me," the farmer observes helpfully.
After battling like sailors in a round-the-world yacht race, we vanquish the elements and three tents were erected. Good team-building exercise, we reckon.
Wake up in bright sunshine to discover what a lovely spot this is with views across a wide bay, and only a gentle stroll away from the village of Aberdaron with its two stores, pub, excellent bakery, tea-shop, and small hotel that was still offering "last-minute vacancies".
Other holidaymakers are not much in evidence, which means the curving beach was mostly empty. This is sea for battling with rather than bathing in, but there are plenty of other distractions for all ages: falling off a windsurfer, building variations on sandcastles - the children make a dragon out of sand; and collecting pebbles, seaweed and yukky things - the younger ones find two dead dogfish and an equally defunct plaice.
Lifting the tent flap reveals ... nothing, apart from a very low, very wet cloud, that appears to have settled in for the duration. We pack picnic and set out on cliff-top walk to St Mary's Well (the Ordnance Survey map shows several wells, and an equal number of sheep-dips).
We meet a sheep-farmer using a quad bike to shepherd his flock, most of which have nasty coughs.
"Do you think the weather'll improve?," we ask.
"Oh, yes," he says. "Next year." This is supposed to be a splendid area for wildlife but we don't find any of the rare crow-like birds called choughs, and the visibility is too poor to see if there are any seals down on the rocks.
Blanche (10 years old) does spot a yellow-hammer which, just as the bird- book says, sings "a-little-bit-of-bread-and-no-cheese". Well, it does if you know that's what it's supposed to be singing. Fortunately our picnic is composed of lots of very good large bread rolls and loads of cheese. Unfortunately, we have to eat standing up as the grass is saturated.
Silas (five) has such wet trousers he can't walk but we carry him and press on to St Mary's Well. It's not easy to find - we heard later of someone who's been looking for it on and off for 50 years. But then you don't expect to find a well halfway up a cliff, which is where it is. Helen (13) thinks the lack of signposting is deliberate, as it's so dangerous getting there.
After my narrow escape from disaster, we fill a bottle with the water "the sweetest in Wales" (according to a man in the pub at Aberdaron), though by the time we get it back to the tent it had begun to pong. Some things just don't travel, do they?
Weather no better. Expedition to buy wellies and socks to nearest town: Abersoch. That's what the grown-ups pretend but the real reason is to stock up on cheaper booze than we can get in Aberdaron. The store there provides sweet little candy-striped bags to conceal your wine-bottle in "in case you meet the vicar'" and perhaps that is what doubles the price.
Abersoch is a good place to buy booze and wellies of all colours. It's a bustling little holiday port full of yachting-types in very clean clothes and unlikely tans. We linger for a while, feeling very unwashed, having coffee and hoping for a sighting of Posh Spice and David Beckham, who are rumoured to have bought a holiday house here. At the end of the day the sun appears in its full glory and we have a barbecue at the end of the beach. Faith (six) is bowled over by the pink tinge that the setting sun gives to the foam on the breaking waves.
We all are. We spend ages throwing the coloured pebbles at a plastic bottle, bank up the bonfire, sing songs and only Silas (five) is worried as he thinks our car will be locked in the car-park.
More rain. Outlook worse. Confined to tents, one of which (mine) has almost collapsed, as a pole has broken Running, or rather sitting-down, repairs are effected. The children don't seem bothered by the weather - the older ones set up a casino in one tent, the others play for hours in the cars and are joined by other small damp waifs from around the camp- site. One of their fathers comes and warns his children that cars (his one anyway) are not for playing in!
The domestic chores seem to stretch out to fill the time allotted. We teach Thomas (16) from Germany how to wash up ("we have machines for this at home"). Thomas puts up good-naturedly with much teasing about his archetypal German habits - he is better acquainted with the camp-site shower (20p in the slot for hot water) than all the rest of us put together. He also has a teutonic capacity for beer, wine, coffee and food, often all at the same time.
Our main meals all comprise variations on what you can cook in a large pot and serve with rice/pasta /potatoes, described as "strange, stewy contraptions" (Alec, 10) and "All horrible except for breakfast" (Silas, 5).
I'm not sure that the local cuisine is a lot better, though the Bramley apple cake at the Y Gegin Fawr tea-house is ace and there's a nice cheese called Bardsey Chieftain (named after an island that's inhabited not by people but by the spirits of 20,000 saints, though we couldn't afford the pounds 100 boat fare to verify this).
No improvement in the weather. Adults becoming rather moody, and, in one case, almost clinically depressed.
We start drinking at lunch-time rather than in the evening. The children, on the other hand seem perfectly sanguine, and join wholeheartedly in the composition of a song about our holiday with the following immortal chorus:
Oh how we love Aberdaron,
Oh what a beautiful bay
The spirits of Bardsey are calling,
A pity the skies are so grey
In the afternoon a trip is organised to Whistling Sands, a beautiful bay owned by the National Trust where a dip in the cold water revives flagging spirits. The rock-pools here are well-stocked and a boy from Manchester called Graham achieves immediate hero-status with our children for his prowess in catching crabs.
Back at the camp, a man and his family arrive with a trailer filled with kites. He's a professional kite-maker and soon the sky is humming with strange flying lilos.
Adults repair to the pub and return at midnight. Thomas the German repairs to another pub and returns with various new acquaintances at 3am.
An ironic but brief burst of sunshine accompanies the taking down and packing-up. We drive home past the rather more conventional holiday sites we might have visited: the stately home at Plas yn Rhiw; a Butlin's holiday camp with day-rates for visitors; the Blaenau Ffestiniog railway; and the extraordinary Italianate village of Portmeirion. I'd like to have stopped off there but by now it is pouring with rain again.
Overall, amazingly enough, everyone seems to have enjoyed the experience. Clarrie (15) says she wasn't at all jealous of her friends who were clubbing in Minorca, and Alec (10) summed it up as "cool".
It certainly was. And wet. And cheap - pounds 4 per family per night for the campsite.