 Other ‘karst’ features such as caves, rock pillars and sink holes abound in this area.On the north-east edge of Dean the Silurian period is represented by the distinctive inlier of May Hill, which rises to some 970 feet, crowned with a pine plantation.This isolated hill lies on the north-south Malvern Line and affords superb views from its summit of the Severn Vale, with the Cotswolds forming the horizon beyond.