which pronounce its position on a hilltop. Significantly, Ruisdael made numerous changes to the castle's setting (it is actually on an unimposing low hill) culminating in a 1653 version which shows it on a wooded mountain. These variations are rightly considered by art historians to be evidence of Ruisdael's compositional skills. On his trip to Germany, Ruisdael encountered water mills which he turned into a principal subject for painting, the first artist to ever do so. Two Water Mills with an Open Sluice, dated 1653, is a prime example. The ruins of Egmont Castle near Alkmaar were another favourite subject of Ruisdael's and feature in The Jewish Cemetery, of which he painted two versions. With these, Ruisdael pits the natural world against the built environment, which has been overrun by the trees and shrubs surrounding the cemetery. Ruisdael's first Scandinavian views contain big firs, rugged mountains, large boulders and rushing torrents. Though convincingly realistic, they are based on previous art works, rather than on direct experience. There is no record that Ruisdael made any trip to Scandinavia, although fellow Haarlem painter Allart van Everdingen had travelled there in 1644 and had popularised the subgenre. Ruisdael's work soon outstripped van Everdingen's finest efforts. In total Ruisdael produced more than 150 Scandinavian views featuring waterfalls, of which Waterfall in a Mountainous Landscape with a Ruined Castle, 1665–1670, is seen as his greatest by Slive. In this period Ruisdael started painting coastal scenes and sea-pieces, influenced by Simon de Vlieger and Jan Porcellis. Among the most dramatic is Rough Sea at a Jetty, with a restricted palette of only black, white, blue and a few brown earth colours. However, forest scenes remain a subject of choice, such as the Hermitage's most famous Ruisdael, A Wooded Marsh, dated 1665, which depicts a primieval scene with broken birches and oaks, and branches reaching for the sky amidst an overgrown pond. Later years During Ruisdael's last period he began to depict mountain scenes, such as Mountainous and Wooded Landscape with a River, dateable to the late 1670s. This portrays a rugged range with the highest peak in the clouds. Ruisdael's subjects became unusually varied. The art historian Wolfgang Stechow identified thirteen themes within the Dutch Golden Age landscape genre, and Ruisdael's work encompasses all but two of them, excelling at most: forests, rivers, dunes and country roads, panoramas, imaginary landscapes, Scandinavian waterfalls, marines, beachscapes, winter scenes,