Outside its urban hub, Madrid doubles as a climber’s paradise

Story by Hayley Masters MADRID–Guillermo Burba dangles by his fingertips from Techo de Puli, a well-known boulder in Madrid’s Sierra de Guadarrama National Park. His tight-fitting t-shirt exposes the veins that bulge along his forearms, while every muscle in his brawny figure flexes simultaneously. Burba is climbing virtually upside down, gripping onto whatever piece of…