Village fought sea-level rise 7,000 years ago. The sea won.

Seven thousand years ago, long before modern industry began to heat the planet, rising seas threatened a community on the coast of Israel. The villagers needed to defend their home, so they built a wall.

It failed. People abandoned the village. The Mediterranean Sea swept inland and drowned the buildings.

But the sea may protect what it ruins. Cool water and a metre-thick layer of sand preserved the paraphernalia of Neolithic life, such as olive pits, bowls, animal bones and graves. The wall stands out: It is a 100-metre row of boulders that runs parallel to the ancient shoreline.

“It’s the world’s oldest seawall,” said Jonathan Benjamin, a marine archaeologist at Flinders University in Australia. “It’s the first evidence of that very real problem that we’re dealing with today” — though he was quick to stress the difference between the source of sea-level rise then (the natural aftermath of an ice age) and now (human-made global warming).

Benjamin and his co-authors claim, in a study published in PLOS One on Dec. 18, that this is the “oldest known coastal defence worldwide.”

The settlement, named Tel Hreiz, was uncovered in 1960 by accident, when divers found flint tools and human bones. Most of the site is submerged about four metres below sea level. It drew little attention until 2012, when strong winter storms shifted the sand cover to reveal a line of boulders. Another storm in 2015 exposed additional stones.

Benjamin and marine archaeologist Ehud Galili, of the University of Haifa in Israel, said the sheer size of the wall, its position and the unusual nature of the boulders all pointed toward one purpose: a defence against the sea.