At the bottom of the caldera, a path and then a spiral staircase (183 steps) lead down into the depths of the abyss. A lake of cold, sulphurous water lies beneath the immense vault of the cave, which is 194 metres long and studded with stalactites. The entrance to the chasm houses the centro de Visitantes da Furna do Enxofre, a long, almost entirely glassed-in box that seems to hang above the pathway, offering information about the site.