These three rough sketches show different views of the Porta San Lorenzo, a gate in the Aurelian Walls also known as the Porta Tiburtina, which today stands near Termini railway station on the eastern side of the city. The shallow arch in the bottom view suggests that this depicts the inner (western) side of the gate which incorporates a white marble arch built by Emperor Augustus to mark the point where three aqueducts entered the city. The middle sketch shows the gate from the outer (eastern) side whilst the top sketch possibly shows the approach from the side.
Turner drew a number of other sketches of the gate, see folios 71 verso and 72 (D15432 and D15433; Turner Bequest CLXXXII 70a and 71) and St Peter’s sketchbook (Tate D16317; Turner Bequest CLXXXVIII 87). He also recorded the distant view of Porta San Lorenzo from the road approaching the inner side, see folios 62 verso and 69 (D15414 and D15427; Turner Bequest CLXXXII 61a and 68).