The beach on the island's northern shore is called Totem Beach, named for the enormous monuments of carved stone in the shape of dragons' heads. The origin of these is unknown either to the barbarians who inhabit the island or to outside scholars. If the dragon's know who carved them, and they probably do, they aren't telling.
The natives of Seren Island are mostly human barbarians of the Seren tribes, who live by fishing, hunting, gathering, and by raiding and pillaging. They offer sacrifices to the dragons, whom they worship as gods.