Ashdown forest is an amazing area. I went to Beacon School, Crowborough , and they sent us on school trips in and around Ashdown forest. I really miss East Sussex, and would love to go back and live there.
But as to the iron rich area, this script is copied from the internet which gives you some idea as to how great the area is. The link takes you to the site, so hopefully the photos will able to be viewed.
"Iron rich stream in Ashdown Forest
Ashdown Forest is a former medieval hunting forest, and is the highest ridge of the High Weald. At ten square miles it is the largest open access area in the South East. Ashdown Forest was purchased by East Sussex County Council from the De La Warr family in 1988. It is now managed by a Board of Conservators. Although nearly two thirds of it is heathland there are also substantial areas of woodland.
This is on the far western edge of Ashdown Forest, beyond the A22. There are also streams as here, viewed from a footbridge. In the 17th century a number of large iron production sites sprung up around the margins of Ashdown Forest with the ore being abstracted from pits within the Forest. Many of the streams, like this, one show up red at times to indicate that iron is present in the soil. Another stream actually showing how red these can be is seen at
Link"