[nik at work]

The at work family is planning to head to the peace and quiet(!!) of Wales for this bank holiday. We consist of a pair of adults, a three year old, a dog and a stupidly large Decathlon pop-up tent. So we're looking for a camp-site for one nights accommodation (Sat), with pretty basic facilities (toilets essential, hot water preferred, hot showers excessive). Ideally somewhere where booking is not required then we can decide on the day what to do (pop-up tent doesn't inspire me if weather is anything worse than benign), and dogs allowed. I'm thinking Llandudno for ice-cream, beach and the cave and bouldering in the pass. We'll have a car.
Over to the travel agents amongst us...

[lagerstarfish]

http://www.shellisland.co.uk/

looks cool, don't take bookings, might be a bit far compared to Llandudno though

[Lund]

The campsite opposite the vaynol in llanberis meets your requirements; it's also cheap.  (The sign outside advertises hot and cold showers.  Why they feel the need to advertise the cold showers, I have no clue.)

The one downside is that it can get a big boggy if it really shells it down for a long time.  The farmer who runs the campsite is pretty friendly though and will pull you out if necessary.

The campsite just up the road from that on the same side isn't as good.

[Zods Beard]

http://www.shellisland.co.uk/

looks cool, don't take bookings, might be a bit far compared to Llandudno though

Shell Island is pretty far from any climbing, some bits of pieces, still and hour or so to the pass. It also gets invaded by scousers on the bank holiday and can get a bit lairy. 

[nik at work]

I've stayed at Shell Island and it was pretty cool. However I've discounted it as I think it's too far away and even tales of lairy scousers are insufficient to persuade me otherwise.

Lund your suggestions sounds just the ticket. The bogginess problem is not an issue as Mrs At Work's built in Living Standards Sensors will be activated in anything worse than a light breeze.

[slackline]

I'll second the recommendation of the pub opposite the Vaynol Arms (although its in ).  The neighbours never caused any problems (probably 'cause they're all six-feet under).

Make sure your tent is well pegged down, my friends were sent rolling by a heavy gust on the Sunday morning last year...

Less lucky! by slack---line, on Flickr

[Lund]

(although its in ). 

Damn, misspoke.  Yes, you're absolutely right.  In nantperis, not far from the end of the village nearest llanberis.