Waterfalls crash down in the depths of the forest. The Cola de Caballo (Horse's Tail), 53m high, is the first surprise, then come the Baño de Diana (Diana's Bath) and the romantic Lago del Espejo (Mirror Lake), wedged between high cliffs. At the end of the itinerary, you can head down a steep, slippery stairway to the very fine Iris Grotto. Finish the tour with a look around the Gothic ruins of the monastery.