More than twenty stratigraphically sequenced excavations have been carried out in the Sierra de Atapuerca (Burgos), at sites dating back to the Middle Pleistocene (730,000-120,000 years old). The different stages of this investigation were initiated in 1978 with a team assembled and directed by Professor Emiliano Aguirre. Beginning in 1982, the excavations began to yield the first traces of human activity. The period between 1988 to 1991 was marked by intense research activity, with the presentation of four undergraduate theses and six doctoral dissertations.

In 1992 a new phase had begun, producing the first ever interdisciplinary team for Quaternary Studies in Spain, made up by specialists from the Biological and Geological Sciences, Paleontology, Anthropology and Archeology from the Universities of Barcelona, Complutense of Madrid, Pierre et Marie Curie of Paris, and Rovira i Virgili of Tarragona. Also taking part were researchers from the Spanish Council for Scientific Research; the General Bureau for Technical and Scientific Research of the Castile-León Committee, among others, offered their financial support. Emiliano Aguirre was one of the founders of the team of which José María Bermúdez de Castro, Eudald Carbonell and Juan Luis Arsuaga are in charge. In July 1992 the discovery of two very complete skulls, in addition to other remains, at the Sima de los Huesos site had a resounding impact on the international scientific community. Discovered were the remains of at least twenty-nine individuals that probably died in a very short period of time and therefore belong to the same biological population that lived in the Atapuerca hills between 200,000 and 300,000 years ago. Beginning in 1994, the remains of hominids dated at 800,000 years old were found, which has converted the investigations carried out in the area into an obligatory frame of reference for the study of European prehistory and bona fide paradigm for the study of human evolution.

At present a permanent exposition is underway which will lay the groundwork for the future Museum of Human Evolution, and a project scheme has been approved for the next fifteen or twenty years which would turn Atapuerca into the European Community´s first archeological park. In March 1997 a documentary was made that will be broadcast on the major European and American television networks in order to reveal the historic discoveries made up to now. Three monographs dealing with the findings will also appear in the "Journal of Human Evolution" later this year.