This is the first of the Neapolitan studies with which Thomas Jones made his deeply original contribution to the oil sketch tradition. He painted it from the roof terrace of his lodgings opposite the Dogana del Sale in Naples.

Beyond the apartment buildings festooned with drying laundry are the wall and tower of the 13th century Castel Nuova, to the left, and part of the roofline of the Palazzo Reale, to the right. The trees of the Largo del Castello stand between them, and the domes of two churches and the lantern of a third animate the horizon.

Examination with infra-red light has revealed extensive pencil underdrawing, with which Jones sketched the principal architectural forms.