Researchers only began to study the rock in 2017.
Brest, France:
A Bronze-age slab first uncovered in 1900 in western France is the oldest map in Europe, according to a study released this week.
The 4,000-year-old object, known as the Saint-Belec slab, is engraved with markings that represent part of the Black Mountains region of western France, said Yvan Pailler, an archaeologist and one of the authors of the study published in the Bulletin of the French Prehistoric Society.
"Today, it is the oldest map of a territory in Europe," he said.
"You can see on the slab carvings which, at first sight, are not understandable.