The horns or needles [Les Agulles] in Montserrat. The particular shapes of Montserrat massif set the so-called Montserrat relief type. Doubtless, the slim monoliths or needles are its most spectacular and characteristic morphology. The current relief of Montserrat comes from the interaction of three elements: the rock material, the structure and the erosion. The material is the conglomerate, a rock made of a different nature stones that are glued in a matrix of sand, clay and calcareous concrete. As a whole, conglomerate rocks are very homogeneous and resistant to the erosion. The structure is a deep deposit of almost flat layers of conglomerate rock with a net of vertical fractures that isolates columns. The erosion by water and ice which is reponsible for sculpting and rounding the columnar structures. [photo Marc Vilarmau]