The beauty of the stalagmites and festoons hanging from the walls is amazing, as is majesty of its spaces: it opens up at an altitude of 880 metres and extends over 850 metres, all of which can be visited. The Cave of Su Marmuri - meaning 'the marble' because of the unusual appearance of the limestone rock - is found one kilometre from Ulassai, a reference point for climbing and trekking enthusiasts. To get to it, you need to take a road situated between rocky outcrops and deep gorges. The immense cavity, formed 150 million years ago by the force of the water, extends along the rocky outcrop known as the Tacco di Ulassai, a massif that overlooks the village.