At the top of the hill, which invites to the building expansion the modern Sarsina, Calbano was certainly for the romans - as it probably was the first for the Umbrians - a 'Arce' (fortress) of secure defense. This is demonstrated by the blocks of sandstone and the numerous bricks of the Roman Age, red between the gray stones of the medieval walls, still visible in many sections. Now the wallworks remained of the "male" (castle) continues to spy on Sarsina and hikers that date back to the hill. But the XVII century church of Sant' Antonio, lying on the side, it attenuates the warrior ardour. Ensure, to the north-west, the entrance to the fortress two circular towers that, cut and transformed for different uses, are truncated cone-shaped at the bottom and cylindrical at the top. Inside, the low houses are aligned inside the ancient perimeter and watching from the stone steps.