My daughter and her husband take the kids to the 'Just So' festival every year. The kids are 5 and 3 and they love it, they look forward to it every year. They take them on at least 3 holidays a year. They do a haven camp that is geared for kids, then they go away with his mum and dad, usually to somewhere abroad and expensive, and they go to the Just So festival, which is like Glastonbury for kids. Out of the 3, both kids and parents enjoy he festival the most. It's in Cheshire too, so not far to go.