This is a place that I would stop off if you out in the area, as it can be a quite quick but it is worth the visit, to get a view into what Neolithic life was like. Also if the weather is right, you can just let the kids run round and burn off some energy.
Grimes Grave is prehistoric flint mine and there are over 400 pits that were dug out. They would dig down and get the flint out and refill the holes. There is a great display the history and importance of the area. Then you can go down one of the excavated shafts. My father-in-law told me that people used to be able to crawl throughout the little tunnels when he visited there 40 years ago, sadly you can no longer do that.
The staff are very knowledgeable and shared with me that the flint from Brandon was used in the guns that Americans used during the American Revolution!
All the Best!
American to Britain