The Roman mansio of El Beneficio Historical milestone · Collado Mediano, Cuenca del Guadarrama, Madrid The site of El Beneficio preserves a Roman mansio, the inn of the road that crossed the sierra by the Fuenfría pass on the way to Segovia. It is the only one excavated and documented in direct association with a road and was declared a Bien de Interés Cultural in 2012. siglos II-V Photo: 1916sem (CC BY-SA 4.0) What to see and do in Collado Mediano