The caves of the Sier­ra de Ata­puer­ca con­tain a rich fos­sil record of the ear­li­est human beings in Europe, from near­ly one mil­lion years ago and extend­ing up to the Com­mon Era. They rep­re­sent an excep­tion­al reserve of data, the sci­en­tif­ic study of which pro­vides price­less infor­ma­tion about the appear­ance and the way of life of these remote human ances­tors.