Archaeologists have discovered a giant ancient Roman oil factory

An international expedition led by the University of Ca' Foscari (Venice) is excavating in the area of the ancient Roman city of Cillium, near the modern border with Algeria, reports Phys.org.

The focus is on massive production complexes associated with olive oil making, including two torcularia - specialised rooms for pressing olives.

Professor Luigi Sperti, Deputy Director of the Department of Humanities and Head of the CESAV Archaeological Centre at Ca' Foscari, has been involved in the work since 2025. The expedition is investigating two ancient olive estates in the Jebel Semmama massif.

The landscape here is represented by high steppes with a continental climate: significant temperature variations, modest rainfall collected in wells. Such conditions were ideal for the cultivation of olives, a key resource of the Roman African economy, which made the territory of present-day Tunisia the main supplier of oil to Rome.

This is the border zone of the province of Africa Pro Consularis, formerly inhabited by the Musulamian tribes of Numidian origin. The region served as a place of trade and contact between the Roman administration, veteran colonists and the local population. According to excavations, the complexes were in operation from around the 3rd to 6th century AD.

One of the key sites is the settlement of Henshir el Begar, identified with the ancient Saltus Beguensis, the centre of a large rural estate in Begua County. In the 2nd century AD these lands belonged to the noble Roman Lucillius Africanus (vir clarissimus).

The settlement is known from a Latin inscription (CIL VIII, 1193 and 2358), which cites a senate decree of 138 AD. - It authorised the holding of bi-monthly fairs, which played an important role in the socio-political and religious life of the region.

The complex itself covers about 33 hectares and is divided into two sectors, Hr Begar 1 and Hr Begar 2. Each is equipped with olive presses, a water harvesting basin and several cisterns.

• Hr Begar 1 contains the largest and most impressive Roman oil mill in Tunisia and the second largest in the entire empire, a monumental torcularium with twelve beam presses.

• Hr Begar 2 preserves a second installation with eight presses of the same type.

These structures were in operation for several centuries, from the 3rd to the 6th century, indicating a long and sustained production. The surrounding area was a rural vicus where colonists and probably part of the local population lived. Numerous stone millstones and millstones were found on the surface - indicating combined grain and oil production and showing the dual agrarian purpose of the estate.

Recent GPR geophysical surveys have revealed a dense network of dwellings and roads, indicating a complex and well-organised layout of the rural space.

The archaeological mission is the result of an international scientific collaboration initiated in 2023 by Professor Samira Sehili (Université La Manouba, Tunisia) and Professor Fabiola Salcedo Garces (Universidad Complutense de Madrid, Spain).

Since 2025, Professor Sperti of Ca' Foscari has been co-director of the project with institutional support from the Italian Ministry of Foreign Affairs and International Cooperation. This status strengthens the scientific partnership and creates new opportunities for joint research between Tunisia, Spain and Italy, especially in the growing field of archaeology of production - including olive oil, which still remains a key element of Mediterranean civilisation.

Valuable finds have been discovered in cultural layers from the New Age to the Byzantine period: a decorated copper and brass bracelet, a white limestone shell and fragments of architectural decoration, among them part of a Roman press reused in a Byzantine wall.

"This mission provides an unprecedented insight into the agrarian and socio-economic organisation of the frontier regions of Roman Africa," notes Professor Sperti.

According to him, olive oil was an indispensable product for the ancient Romans: it was used not only in cooking, but also for body care, sports and medicine, and low-grade oil was used as fuel for lighting.

"By revealing on such a scale the processes of production, trade and transport of this product, we have a unique opportunity to combine basic research, heritage promotion and elements of economic development, once again confirming the importance of archaeology as a strength of our university", emphasises the scientist, as reported by Ca' Foscari University of Venice.