Looking for campsite/holiday park with pool & waterslides

[johnnybuoy]

Can you recommend a campsite near the coast in Southern England or Wales which has indoor pool and water slides and ideally other facilities for a 9 and 7 year old?
Ideally it would be within about 5 hours drive of London.
We've been to Hendra holiday park in Cornwall previously which has such facilities and is very good but it now costs almost £400 for camping for 8 nights which seems a tad expensive.
We're looking for somewhere to go during the May half-term.
Thanks.

What about Park Resorts at Camber Sands in East Sussex or my personal favourite, Oakdene in the New Forest. You can't actually camp there but they have a sister site nearby and you can use Oakdene's facilities. Park Resorts is probably better if you want lots of onsite entertainment but Oakdene (a Shorefields site) is smaller and I think a bit nicer. Not right by a beach though like Park Resorts.

Kelling heath? Not sure about the slides but fab site and a pool.

The haven park in perranporth Cornwall has indoor and outdoor pool with fumes plus footie,crazy golf, playground etc just came back from there