What to do anywhere between Birmingham & Kent?

[TooMuchCheesecake]

We are planning to take to kids (5&2) to Drayton Manor for a day, staying overnight in Tamworth, then head towards home the next day. We would like to visit somewhere on the route home, spending half the day there. Could be anywhere between Birmingham and Kent. Any recommendations?

I'm planning on doing this in the summer but returning to the north east.

I keep looking at Cadbury's World, which the DC ( 7&4 ) think they want to do, but cant help thinking it might be naff for the money. Ive seen some suggestions for Think Tank in Birmingham and the Black Country Museum. There is also a snow dome type place in this area. There is a safari park but if you go to the zoo in Drayton Manor im not sure if this would be worthwhile.

Drayton Manor offer next day for £12 each would you consider utilising this?

Ive also been looking at Sandwell Valley Country Park

I took my kids to Go Ape and they absolutely loved it! I think there are a couple in the South so you can choose which one to go to! We took our own picnic as well and then went for a walk in the Forest, really good day out!