The walled garden, which had originally been the garrison's vegetable plot, was designed by Lutyens' long-time friend and collaborator, Gertrude Jekyll between 1906 and 1912. It is some distance away from the castle itself. Between 2002 and 2006 it was restored to Jekyll's original planting plan which is now held in the Reef Collection at the University of California, Berkeley. The castle, garden and nearby lime kilns have been in the care of the National Trust since 1944 and are open to visitors.