Shaped by water, this natural way used by the Romans is a witness to the history of the region. At the northern foot of the pass is the source of the Birse.
The Pierre-Pertuis pass which connects the villages of Sonceboz and Tavannes is at the same time an amazing natural site of greenery but also a witness of the history of the region. While walking along the pass, the hiker follows the Roman road, built during the period of Emperor Marcus Aurelius, and sees on his way the famous pierced stone of Pierre-Pertuis. The path is embellished with four didactic panels that inform the hiker about the source of the Birse, the literature and history, the geology and the Roman road. Not far away is also the source of the Birse, which can be visited on request to the public utility services.