The archaeologists were investigating the site of an ancient battlefield in Oberhalbstein, where the Romans were conducting a campaign against the local Suanetes tribe (identified by Pliny as the Raeti) in order to gain control over the Alps.
After conducting a survey using LiDAR technology in the surrounding area, the archaeologists were able to identify traces of a Roman military camp. Light Detection and Ranging (LiDAR) is a remote sensing technology that uses pulsed laser light to measure distances to the Earth's surface. By analyzing the time it takes for laser pulses to return and the wavelengths involved, LiDAR can be used to create detailed digital maps of landscapes.
The camp was fortified with three ditches and a wall, occupying a strategic location that allowed defenders to control access to the surrounding valleys through mountain passes.
Following a series of geophysical surveys, exploratory excavations revealed weapons used by soldiers, such as slings and hobnails; some slings bore the mark of the Third Legion, along with those of the Tenth and Twelfth Legions from 15 BC.
According to researchers, the discovery of a Roman military camp in Graubünden allows for precise tracking of Roman troop movements 2,000 years ago from Bergil through the Septimer Pass to the Tifenz Castle area, and then onward towards Coire and the Alpine Rhine Valley.