This is the classic and best-known mountaineering route on Peña Santa de Castilla. It is a serious alpine limestone ascent rather than a hiking path, with route-finding on broken rock and exposed sections. The terrain is typically steep, loose in places, and can be affected by poor visibility because the mountain is complex and rugged. The route is usually approached from the Vega de Ario area, often with a refuge-based strategy. Conditions on the upper mountain can make the difficulty feel higher than the nominal grade. It is the standard line most commonly described in guidebooks for this peak.