During his 1819 visit to southern Italy, Turner made several sketches of the Bay of Baiae, an ancient Roman bathing resort situated on the coast approximately ten miles west of Naples. These formed the basis for a later oil painting, one of three Italian subjects completed by the artist in the months and years following his return to London in 1820. The painting, The Bay of Baiae, with Apollo and the Sibyl exhibited 1823 (Tate, N00505),1 features a similar view to that depicted here, looking south-east across the bay towards the distant Posillipo coast, with the so-called Temple of Diana, a ruined thermal bath-house with a half-dome vault, on the left. Turner’s viewpoint for this drawing is very close to the so-called Temple of Venus, an octagonal ruin which appears with the castle of Baiae on the opposite sheet of the double-page spread, see folio 84 verso (D15722; Turner Bequest CLXXXIV 82a).
Martin Butlin and Evelyn Joll, The Paintings of J.M.W. Turner, revised ed., New Haven and London 1984, no.230.