A door on the right gives access to the great well that drops about 60 m below the level of the River Inn. From here, a rocky underground corridor, about 170 m long, leads to the "Peacock's Tail" Gate (Pfauenschweif), then to the Wallachen bastion and finally to the Caroli bastion, where a fine viewpoint overlooks the River Inn and the wooded slopes of Pendling.