The Pleistocene site of Gran Dolina, Sierra de Atapuerca, Spain: a history of the archaeological investigations.

Gran Dolina is part of an archaeological and paleontological complex located in the Sierra de Atapuerca karstic system (Burgos, Spain). The Trinchera del Ferrocarril sites were discovered as a consequence of the construction of a railway for the transport of minerals at the end of the nineteenth century. The systematic excavation of the upper Gran Dolina levels was initiated in 1981. In 1993, a 6 m(2)biostratigraphic survey pit was started, reaching level TD6 in 1994. This level was excavated during four consecutive years, yielding human fossils, identified as Homo antecessor, in association with lithic and faunal remains, dating to more than 0.78 m.y.a.