Bronze Age bone punches. These tools, also called awls or perforators, were tapered and worked pieces of bone used to punch holes in animal skins or leather when making clothes. These bone punches, found in 2004, are from the Portalon cave (the entrance cave) to the Cueva Mayor, a cave in the Sierra de Atapuerca foothills near Burgos, Spain. Bone punches have been found in this cave at the Early Bronze Age level, dating to around 1690 BC. The limestone caves in these hills, containing many prehistoric fossils and artefacts, have been designated a UNESCO World Heritage Site.