Turner’s exploration of Tivoli included a large number of landscape sketches drawn from the river valley to the north. This page contains part of a panoramic view drawn from the floor of the valley looking towards the northern tip of the town. The drawing continues on the opposite sheet of the double-page spread, see folio 48 (D15016), but visible on this side is the vista looking south-west down the valley. The spur of land at the left of the composition, topped by a medieval watch-tower, is the point where part of the River Aniene flowed from an underground passage and emerged in cascades down the slopes. The ruined Santuario di Ercole Vincitore (Sanctuary of Hercules the Victor), is just out of sight beyond, whilst visible on the far horizon is a tiny dome indicating the distant St Peter’s in Rome. A similar view can be seen in a drawing by James Hakewill (1778–1843), Tivoli. The first fall of the Cascatelli 1817 (British School at Rome Library).1
Tony Cubberley and Luke Herrmann, Twilight of the Grand Tour: A Catalogue of the drawings by James Hakewill in the British School at Rome Library, Rome 1992, no.5.6, p.229, reproduced.