Perched on a 962m-high rocky peak, this Benedictine abbey built in the 10C by Hughes de Montboissier is similar in design to the Abbey of Mont-Saint-Michel. The Stairway of the Dead leads you to the Zodiac door (pilasters and capitals decorated with sculptures by the "maestro Nicolo"). Situated at the very top of the rock, the Romanesque-Gothic abbey-church is decorated with 16C frescoes. From the esplanade, enjoy superb views over the Dora Baltea valley and mountains.