Roof of the Bontnewydd Cave. The Bontnewydd Palaeolithic site is an archaeological site in Wales which has yielded the earliest known remains of Neanderthals in the region. It is located on the River Elwy, near the hamlet of Bont-newydd, Conwy. Teeth and part of a jawbone excavated in the cave in 1981 were dated to 230,000 years ago. The bone is from a Neanderthal boy approximately eleven years old.