Deep cuttings were made through the karst geology exposing rocks and sediments of features known as Gran Dolina, Galería Elefante and Sima de los Huesos.Further excavations followed, and interdisciplinary work has been undertaken by several teams, led by Emiliano Aguirre from 1978 to 1990 and later jointly by Eudald Carbonell, José María Bermúdez de Castro and Juan Luis Arsuaga.The combined work of archaeologists Jesús Carballo (1910 to 1911), Geoffrey Clark (1971), José María Apellániz (1973 to 1983) and the current team of Juan Luis Arsuaga accounts for the documentation of the excavation sequence of ceramic objects from all relevant sediment layers since the Neolithic.Its sediments were divided into eleven stratae (TD-1 to TD-11) Sima de los Huesos (Pit of Bones) accounts for the greatest number of valuable scientific discoveries and knowledge acquired with far-reaching implications.It has received a surprisingly high degree of attention, and a number of experts support the hypothesis that this particular Acheulean tool made of red quartzite seems to have served as a ritual offering, most likely for a funeral.
Trinchera Zarpazos, part of the Galería system, in 2006