After Civita Castellana, Turner’s route to Rome left the Via Flaminia and led him south-west to Nepi, a town approximately twenty-three miles north of the Eternal City. Nepi’s main landmarks were the fifteenth-century castle, the cathedral, and the subject of this sketch, the eighteenth-century aqueduct built by Filippo Barigioni (1690–1753) which still stands today just outside the north-east corner of the old town. Turner’s sketch depicts the aqueduct from the walls on the northern side of Nepi. In the background is the main part of the structure with a double tier of arches, whilst in the foreground is another single row. Gillian Forrester has suggested that the aqueducts seen by Turner during his travels through Italy in 1819, such as this one at Nepi, may have informed the composition and subject-matter of The Stork and the Aqueduct, (Tate, A00152), a ‘Liber Studiorum’ plate, dating from the early 1820s.1
Further studies related to Nepi can be found on folios 76 verso (D14802) and 81 verso–83 verso (D14812–6). See also Turner’s 1828 sketches in the Viterbo and Ronciglione Sketchbook (Tate D21788–D21808; Turner Bequest CXXXVI 12a–22a), particularly Tate D21791; Turner Bequest CCXXXVI 14 which repeats the composition of this view of the aqueduct.
Forrester 1996, pp.147 and 148 note 4.