Mallos

Mallos is the term used for a group of tall rock formations found in northern Spain, with the best known example being the Mallos de Riglos near the village of Riglos in Huesca province, Aragon. The word mallo, used in Aragonese and Spanish, denotes a large crag or cliff, and Mallos refers to multiple such towers.

The Mallos de Riglos consist of several vertical pillars and sheer faces that rise prominently from the Ebro valley. They are formed mainly from dense sedimentary rocks, often described as a conglomerate and sandstone sequence from the Tertiary period, which were uplifted and subsequently sculpted by erosion to create the characteristic pinnacles. Heights of the individual formations can reach several hundred meters, producing dramatic silhouettes that are visible across the surrounding landscape.

Ecology and landscape value are notable aspects of the Mallos. The surrounding area provides habitats for raptors such as griffon vultures and peregrine falcons, and the cliffs attract a variety of intermediate to advanced climbers who seek the region’s renowned routes. The scenery also makes the site a popular destination for hikers and nature observers, with viewpoints that offer expansive perspectives on the pinnacles and the Pyrenean foothills.

Etymology and usage: Mallos is used to describe these vertical rock structures in regional Spanish and Aragonese, and the term is applied to this specific cluster of formations as well as to other similar cliff/stack groups in the region. The area remains a key example of limestone and sandstone geologic processes that create dramatic, enduring landforms.