A labyrinth of tunnels carved into the rock, opening spectacularly onto sheer views of the island's south-west coast. The tour of the Henry tunnel, which has been made safe and can be visited with prior booking, is a journey through time inside the Pranu Sartu mine, Buggerru's most famous and productive mine. On the way out, you can take an electric train along the route of the old steam railway, and on the way back you can walk along the old 'pedestrian' tunnel, which was once used by pack mules. Walkways carved into the rock run the length of the cliff: some sections are in the dark, broken every now and then by the light coming from huge windows carved into the mountain face and overlooking the sea. The most spectacular view is at the end of the route: 50 metres above sea level, with a breathtaking backdrop overlooking the coast and the village's houses.