The topmost parts of the forest exhibit several Bronze Age round barrows, and there are also several ring cairns in the area. Most occur on or near the peaks, such as Black Mixen and Bache Hill. Prehistoric settlement is shown by hut circles often present as distinctive platforms. The forest was exploited as a military training area in the last war, and has remnants of such activity such as bomb craters and slit trenches. Part of the site is still used for testing ammunition and ordnance; there are warning flags and signs at the boundaries of the Harley valley range. It includes a distinctive landscape feature known as The Three Wriggles, a set of three gulleys running down the mountain slope on the western side of the Harley valley. There is also some evidence for mining activity.