The town of Dumbarton (Dunbritton) and Dumbarton Castle (Dunbritton Castle) are the main features of this detail, which follows the north shore of the Clyde upstream past Kirk of Kilpatrik (near present-day Old Kilpatrick). This part of the map has been drafted by Robert Gordon, who worked on Pont's maps after his death.
Detail from Pont Map 32
See also detail from Pont Map 33 for another depiction of Dumbarton
Dumbarton also appears, in much less detail, in Pont Map 17