Other weapons are bone spearheads and flint arrowheads. They harvested berries, made baskets, hunted, and made obsidian arrowheads and spears. Materials used in the past for arrowheads include flint, bone, horn, or metal. Pottery and bronze arrowheads dating form this period have been found. Stone arrowheads, knives and scrapers from the era are commonly found. Their tools, including scrapers, chisels and arrowheads, were discovered in 1973 through archaeological excavations. In addition, they found Greek arrowheads, slingshots, ballistic stones and amphorae. In many cultures it was shaped by cold hammering into knives and arrowheads. Traces of seasonal camps, characterized by arrowheads, scrapers, and other similar tools have been found. Once treated, the heated rocks were modified and tempered into crescent shaped blades or arrowheads. Among these remains are arrowheads and charred remains. The earliest known inhabitants were probably San people, who left behind arrowheads and cave paintings. Sailing up a river, they are attacked by skraelings armed with stone arrowheads. Glissandi are represented by diagonal wavy lines with arrowheads at the end. A number of bronze arrowheads were also found at the site.