At the heart of the Haute Bléone, the summit of Estrop, the highest point of the Trois-Évêchés massif and the Geopark, towers above the Alpes de Haute-Provence département at an altitude of 2961 meters. Its geology is marked by Annot sandstone, a slightly pink nummulitic sandstone resting on blue marl and limestone from the Cretaceous period (145 million to 66 million years ago).

Its rugged surroundings, devoid of any permanent population, mean that it cannot be reached directly by car. The hike is more accessible in two days, with an overnight stay in a refuge. At the summit, a 360° panorama offers breathtaking views.