I was told that West Ilsley was worth a visit and it is. A lovely little playground - with cows looking over the fence, a large green and a pub. Take some duck food - there's a pond, too.
Find this park on the google map I made for you.
To get to West Isley is really simple. Go south (from Didcot) down the A34, take the first slip road, go over the bridge following the directions to West Ilsey - you'll be travelling along Bury Lane for a little while. When you get to the village, turn right along the 'Tour of Berkshire'. The park is on your left hand side. You really can't miss it - it is really easy to find.
There's no designated parking, we parked along the road outside the farm but the road isn't busy.
My children really enjoyed this playground and we were there for 1.5 hours. I really like that the swings are sectioned off a bit from the rest of the equipment and in a corner.
There is equipment for children of all ages, little swings, big swings, a big slide, little slide:
The pub - The Harrow - is the white building in the centre of the page. They very kindly allowed my children to use their facilities.
You can get to the Ridgeway from Bury Lane. There is designated parking either side of the road.