Somosierra, Mountain pass between Community of Madrid and Segovia Province, Spain
Somosierra is a mountain pass in the Sierra de Guadarrama, connecting the northern edge of the Community of Madrid with the eastern part of Segovia Province at around 1,440 meters. The A-1 motorway crosses the area through a tunnel, while the old road still climbs to the actual top of the pass and offers open views of both sides.
The pass was used as a crossing route in Roman times and served as a trade road between the Castilian plateaus through the medieval period. In 1808, a battle between Napoleonic forces and Spanish defenders took place here, after which the French advance toward Madrid continued.
The pass marks the boundary between the Community of Madrid and the Province of Segovia, and crossing it on the old road gives a clear sense of moving between two different worlds. The stone walls, vegetation, and village architecture shift noticeably from one side to the other.
Visitors arriving by car should take the exit from the A-1 motorway to reach the old mountain road, which is clearly signed and accessible by vehicle or on foot. During winter months, snow and ice can close the old road, so it is worth checking conditions before heading up.
Beneath the pass runs an old railway tunnel of about 4 kilometers that was abandoned in 2011 when train services through the route ended. The tunnel entrance is still visible from the road, though the interior is not open to visitors.
The community of curious travelers
AroundUs brings together thousands of curated places, local tips, and hidden gems, enriched daily by 60,000 contributors worldwide.
