To reach the entrance of the valley, from San Giovanni Rotondo take the provincial road to Manfredonia, where a dirt road is indicated which leads to a small farmhouse. On the right you take a panoramic path that cuts across the side of the valley that disappears after half an hour of walking. You will suddenly reach a sort of balcony with a view of the Gargano roof (Monte Calvo, 1,055 meters). Continuing zigzag between the rocks, to the right, is the high entrance to the Grotta Grande. This beautiful subterranean complex, arranged on several levels, is the wreck of a cavity that was much more extensive and reduced by the evolutionary retreat of the valley. From a first cave you go down into a small corridor that takes a shelter. At the bottom, you gain access to a narrow passage that leads to a large hall. The path descends to a large entrance overlooking a vertical wall (be careful not to lean). Go up the whole cave and cross the summit plateau, then go down comfortably along the slope and reach the bottom of the valley at the entrance cartway.