An initial 5-day sounding was made in 1967 by M.N. van Loon and R. H. Dornemann with a trench at El Kowm I; a large
Neolithic tell about in size. They categorised their findings into 5 periods; Early Neolithic (A), Middle Neolithic (B–C), Late Neolithic (D) and Post-Neolithic (E). Further excavations were made into a small outlying tell called El Kowm II by
Danielle Stordeur between 1978 and 1987 by the
French Ministry of Foreign Affairs permanent mission to El Kowm-
Mureybet (Syria). The Neolithic stages at this smaller outlying tell showed one of the first places where domestic water and wastewater systems have been installed. Further surveys and fieldwork were carried out from 1980 onwards by Jacques and M.-C. Cauvin,
Lorraine Copeland, Francis Hours, Jean Marie Le Tensorer and S. Muhesen. Since 1989 further research has been carried out by the Institute for Prehistory and Archaeological Science of the
University of Basel and the Department of History at the
University of Damascus. These have concentrated on
Paleolithic sites at El Kowm called Nadaouiyeh Aïn Askar, showing periods of inhabitation between 500,000 and 100,000 BP, and Hummal, showing evidence of human inhabitation of over 1 million years through the
Oldowan and Hummalian blade industry periods. Another period was identified under the
Yabrudian levels that has been tentatively named as
Tayacian. ==Major discoveries==