The region has been inhabited since at least the Bronze Age, although settlement of the higher elevations was slow and initially the population was concentrated in the valleys. Bronze Age tumuli have been found north of Alzenau, near Geiselbach and Mömbris as well as near Pflaumheim, southwest of Aschaffenburg.: Other tumuli were found near Kleinwallstadt, between Elsenfeld and Eichelsbach, near Klingenberg and on the Dürrenberg near Heimbuchenthal. The discovery of numerous prehistoric tools and weapons indicates that the Spessart was frequented by hunters, gatherers and fishers. These findings have been concentrated in the valley of the Kinzig, around Aschaffenburg, as well as in the valleys of the Bieber, the Lohr and the Sinn rivers. Near Goldbach, early Iron Age artifacts have been found, attributed to the Hallstatt culture.: Hill forts attributed inter alia to Celts of the La Tène culture have been found on the Schanzenkopf near Wasserlos, on the Schloßberg near Soden/Sulzbach, on the Schanzkopf near Klingenberg and close to Miltenberg (Greinberg and Bürgstadter Berg, although the latter dates to the Urnfield period and/or even earlier Michelsberger culture). These fortified refuges or defended hill-top settlements were mostly built between 500 and 100 BC.