How a Bronze Age rock became a 'treasure map' for researchers

A piece of rock with mysterious markings that lay largely unstudied for 4,000 years is now being hailed as a “treasure map” for archaeologists, who are using it to hunt for ancient sites around north-western France.

The so-called Saint-Belec slab was claimed as Europe’s oldest map by researchers in 2021 and they have been working ever since to understand its etchings—both to help them date the slab, and to rediscover lost monuments.

The ancient map marks an area roughly 30 by 21 kilometers and Pailler’s colleague, Clement Nicolas from the CNRS research institute, said they would need to survey the entire territory and cross reference the markings on the slab.

That job could take 15 years, he said.