I'm really interested, too!

The Friends of Blythe Hill Fields always have a good stall at the annual festival, with historical maps and photos of the area (sadly it's just been and gone and I missed it this year due to being on holiday).

The thing that always fascinates me is it having been crossed by the Roman London to Lewes road.

I believe it, or at least part of it, was brickfields used for the local housing, and it was made into a park in the 1930s.