 The caves contained traces of fires, spear points carved from reindeer antler, and pendants made from snail and mussel shells.From the end of the Palaeolithic era, Birseck–Ermitage cave contains "galets colori", red-stripe-like painted limestone pebbles, and flint tools.From the Mesolithic period (6000–5000BC), flint tools have been discovered at the Abri overhang at Hohlefels, excavated in 1905 by Fritz Sarasin, and in the Birseck–Hermitage cave.