Northern borneo, the area that is now sarawak had entered the iron age by ce 600. sarawak river delta have revealed much evidence not only of early iron working but also of extensive trade with china and the southeast asian mainland offered edible bird’s nests, rhinoceros horns, hornbill "ivory" (from the casque atop the bird’s beak), camphor, spices, wood, and other goods in exchange for chinese ceramics, metal, and probably clothing. meanwhile, neolithic boat builders along the east coast of present-day sabah were involved in extensive interregional trade; the maritime peoples