Letting off steam near Milton Keynes for a long journey?

[PatCandlestick]

I'm doing a journey from Andover to Huntingdon and need a stop off point to let DC (7 and 4) let a bit of energy out.

Ideally it would be about 60-90 mins from Huntingdon, so it looks like somewhere near Milton Keynes would be good, but can also do nearer our start as will also do something on the way back.

We only want to be there for about 1-2 hours max, so thinking a forestry England type place, minimal cost, an interesting walk and playground with a cafe kind of thing. We don't want somewhere that would be a big day out like Gullivers. Or maybe a really good soft play that might be different from our usual ones? Or a small, low cost farm? Happy to pay parking or a small entrance fee but don't want to pay loads as we won't be there for long.

Any suggestions please?

Aye, I thought it was going to be a whole day journey!

Willen lake definitely.

Salcey Forest is very good, lovely little playground and sand play area although parking is quite expensive there. For free entry I would suggest Furzton Lake, Ouse Valley Park, Caldecotte or Howe Park Wood.

If you are taking the A421 there's a country park at Stewartby just after Milton Keynes.

Following as we live about half way through your route and so interested in hearing ideas!

Some of these are a bit off track (and not near MK) but sort of on the route if you go m25 way but there's Cliveden (NT), Wendover Woods (Forestry England), Black Park, Rickmansworth Aquadrome, Langley Park, Cassiobury Park (Watford), Leavesden Park - all of which we really like with young kids.

Thanks for all the suggestions, we are likely to be doing the same journey in the future so will work our way through them!