Ancient Neolithic villagers on the Carmel Coast in Israel built a seawall to protect their settlement against rising sea levels in the Mediterranean, revealing humanity's struggle against rising oceans and flooding stretches back thousands of years.

An international team of researchers from the University of Haifa, Flinders University in Australia, the Israel Antiquities Authority and The Hebrew University uncovered and analysed the oldest known coastal defence system anywhere in the world, constructed by ancient settlers from boulders sourced in riverbeds from 1-2km near their village.

In a study published today in PLOS ONE, Dr Ehud Galili from the Zinman Institute of Archaeology, University of Haifa, explains that the over 100 metre long seawall proved to be a temporary reprieve and the ancient village was eventually abandoned and inundated.

This discovery provides new insights into ancient human responses to current threats posed by sea level rise.1

  • 1. Current estimates predict 21st century sea level rise to range from 1.7 to 3mm per year, representing a smaller change when compared to the threat experienced by the Neolithic community that built the ancient sea wall, however many of the same challenges will be posed according to the authors.

    "Many of the fundamental human questions and the decision-making relating to human resilience, coastal defence, technological innovation and decisions to ultimately abandon long-standing settlements remain relevant." says Dr Galili.

Fig 1. Location maps.
Fig 1. Location maps. - (a) Eastern Mediterranean and the Israeli coast; (b) submerged Neolithic settlements off the Carmel coast. © J. McCarthy after Galili et al. 2019, modified after Natural Earth, https://www.naturalearthdata.com in the public domain

Ehud Galili, Jonathan Benjamin, Vered Eshed, Baruch Rosen, John McCarthy, Liora Kolska Horwitz. A submerged 7000-year-old village and seawall demonstrate earliest known coastal defence against sea-level risePLOS ONE, 2019; 14 (12): e0222560

DOI: https://doi.org/10.1371/journal.pone.0222560

We report the results of underwater archaeological investigations at the submerged Neolithic settlement of Tel Hreiz (7500 – 7000 BP), off the Carmel coast of Israel. The underwater archaeological site has yielded well-preserved architectural, artefactual, faunal and human remains. We examine and discuss the notable recent discovery of a linear, boulder-built feature >100m long, located seaward of the settlement. Based on archaeological context, mode of construction and radiometric dating, we demonstrate the feature was contemporary with the inundated Neolithic settlement and conclude that it served as a seawall, built to protect the village against Mediterranean Sea-level rise. The seawall is unique for the period and is the oldest known coastal defence worldwide. Its length, use of large non-local boulders and specific arrangement in the landscape reflect the extensive effort invested by the Neolithic villagers in its conception, organisation and construction. However, this distinct social action and display of resilience proved a temporary solution and ultimately the village was inundated and abandoned.