Barsalloch Fort

Aspects of the Barsalloch Fort site are thought to date to the Mesolithic period, the era of Galloway's earliest inhabitants. In the wider region, later prehistoric activity is marked by Neolithic monuments such as the Drumtroddan standing stones, the Torhousekie stone circle and the Cairnholy chambered cairn, together with one of the earliest pit-fall traps known in Europe, discovered near Glenluce in Wigtownshire.

By the Iron Age the site was occupied by the Novantae. In Galloway this is the period where prehistoric archaeological remains and recorded history first overlap, and the region's characteristic monuments of the age were crannogs, promontory forts and duns. Galloway held a notable concentration of crannog-type sites, a pattern owed partly to a landscape that favoured lochs and partly to those lochs being drained comparatively late, which left more undisturbed sites for later investigation.

The Novantae are known chiefly through Roman geography. After the general Gnaeus Julius Agricola campaigned northward and reached Scotland around AD 79, the Alexandrian geographer Ptolemy produced his Geographia around AD 150, drawing in part on a now-lost atlas by Marinus of Tyre. Ptolemy listed two peoples in the area around Galloway: the Novantae in the west, associated with Wigtownshire, Kirkcudbrightshire and southern Ayrshire, and the Selgovae in the east. The Iron Age inhabitants of Barsalloch are thought to have been Novantae, as were those of the Rispain Camp site.

The Novantae territory around Whithorn appears to have grown into a local power centre later in the Iron Age. Rispain Camp, a multiple-household settlement near Whithorn, contained a form of bread wheat unique among Iron Age sites in Galloway, while the coastal site at Carghidown yielded lead beads whose isotopes pointed to the Scottish Southern Uplands as a likely ore source. Together these sites suggest a settled and, in places, prominent community across the peninsula in the centuries around the Roman conquest.