Ancient Roman ruins that lie hidden below the surface at the Apennine Mountains of Italy have largely escaped discovery because the rugged terrain makes them difficult to spot by foot and dangerous to find by airplane. Now, using small airborne drones, archaeologists have found that an ancient settlement in the Apennines was much more dense and organized than previously thought, a new study reveals. The study offered evidence that drones could help uncover more unknown sites in mountains worldwide. Scientists investigated the area of Le Pianelle in the Tappino Valley in the mountainous southern Italian region of Molise. This area was known as Samnium in antiquity. “The way this mountain society was organized remains poorly understood,” said study author Tesse Stek, a Mediterranean archaeologist at Leiden University in the Netherlands. Previously, construction accidentally unearthed two ancient temples in the area. However, “there was no good knowledge about other sites, such as villages, farms, villas, graveyards and so on, that could tell us more about the ancient inhabitants in the area that visited the cult sites,” Stek told Live Science. “They seemed to be cathedrals in the desert, so to say.” One theory is that these temples served as road stations and places of commerce along routes where sheep, cattle, goods and information traveled. Another theory suggests that these temples marked the frontier of a large state, such as the territory of the ancient Samnites.