Domestic holiday ideas for a couple with a baby? Static caravan parks you can recommend?

As the title suggests we are hoping to take a holiday in the UK but looking for suggestions of where to go that will cater for a couple with a young baby.

We're on a pretty tight budget so I think holiday homes are out and, having a small baby, we'd need to be back to wherever we're staying by about 9 at the latest, so hotels would be pretty dull - couldn't exactly leave her there to go out to a bar. So we thought maybe staying in a static caravan park could be a good compromise - we could do day trips and go out for nice lunches in the day then cook nice dinners and hopefully enjoy some evening sunshine back at the caravan at the end of the day.

So, can anyone recommend anywhere that fits the bill? We're willing to go almost anywhere but I am visiting my parents in Kent soon so somewhere around that neck of the woods or just north of London would be ideal. Somewhere with things to do locally (zoos, nice walks, aquariums, pubs, beaches - anything really!) as well as good onsite amenities (pools, bars, restaurants, nice views, that sort of thing).

I've done a bit of googling but not come up with much - mostly because there are too many options for nice areas in the country so narrowing it down by location is tough. I also don't know what to look for in terms of a caravan park that has caravans we can rent for a reasonable price.

Any sort of hints or tips, recommendations etc. are gratefully received! You'd make a new dad very happy!