Please note as of January 2019, the National Trust has removed the stile allowing access to the east park. Notices indicate the need to protect the deer. While no dogs must enter this area, you must make your own decision as to whether to enter. Much of the military archaeology lies here and if approached by a Park Ranger explain your interest, but it is likely that you will be asked to leave.
Monthly ranger walks allow some access to this important military archeological site. Ask the guide to show you at least some of the above ground archaeology.