Take the C-8 from Atocha or Chamartín to Cercedilla (~80 min), drop the bag at a hostal near the station, and ride the C-9 mountain line up through the pines to the Puerto de Navacerrada — or on to Cotos for the Peñalara lagoons if the day is settled. Walk down the Camino Schmidt back to Cercedilla (11 km, gravity-assisted, yellow dots the whole way) and be at a chocolatería table by 17:30. Dinner is a mountain menú — judiones, roast, flan — 50 metres from your bed.
Morning on the Calzada Romana: 2,000-year-old paving up the Fuenfría valley to the 1,796 m pass and back by the miradores track (10 km round). Long lunch in the village, then the C-8 home — you’re back at Atocha before the Sunday evening trains fill. Total transport cost with a zone-T Tourist Pass: the price of two city cocktails.
Swap Cercedilla for San Lorenzo de El Escorial (bus 661/664 from Moncloa) to trade the second walk for Philip II’s monastery. Or go north instead: bus 191 to Buitrago’s walls with a Saturday night inside them. Winter versions of all three work — the C-9 runs snow services and the roast lunches improve with the weather’s deterioration.
Curated picks are coming — meanwhile, the live search covers every bookable property at the same price or better.