The Bridge of the Seven Arches and the head of the canyon Monument · Santa María de las Hoyas, Tierras del Burgo, Soria The seven-arched viaduct that carries the road towards San Leonardo marks the upper entrance to the canyon of the río Lobos, where the gorge is still wide and the river runs among pine woods before cutting into the limestone. Photo: José Ibáñez (CC BY 3.0) What to see and do in Santa María de las Hoyas