This sketch depicts part of the sixteenth-century Villa d’Este, in Tivoli. The view looks south across the gardens towards the casino from the Organ Fountain, a hydraulic water feature which was designed to push air through a series of pipes to emit sound. The tall circular structure behind the fountain is the apse of the Church of San Pietro alla Carità. In the top right-hand corner is a smaller sketch of another detail of the gardens.
For a full discussion of Turner’s sketches of the Villa d’Este see folio 5 verso (D14942).