OverviewThis is the easiest route -as far as I know- to the summit of La Maliciosa, meaning only a 10 km hike to get there and back to the parking lot. An easy hike, for sure, available to most people with a basic physical training. All you have to do is walk uphill: a dirt road can take you from the Puerto de Navacerrada to the summit of the Bola del Mundo, and afterwards all you will have to do is stroll down to the Collado del Piornal and grab the summit of La Maliciosa. About two hours to get to the top (make it three and a half to four for the whole hike), a nice walk and (weather allowing) great views of the area around the mountain.
Getting ThereSiete Picos and Bola del Mundo. And, of course, a ski resort means buildings, bars, restaurants and so on. A good number of facilities allowing you to buy food or drinks but taking away most of the charm of the landscape.
By car:Puerto de Navacerrada is 64 km away from Madrid, driving northwest. The best driving option is to take the A6 motorway for 43 km, up to exit 39 (signposted as “Villalba/Puerto de Navacerrada”). Leave the motorway and take road M-601 (grossly northwards) to Navacerrada (about 13 km to go) and Puerto de Navacerrada (an additional 7 km, making 20 km from the motorway).
Another option would be the M-607 highway to Colmenar Viejo, continuing afterwards to Cerceda and Navacerrada to enter there road M-601 to Puerto de Navacerrada. This second option offers a better landscape and might be helpful in case of heavy traffic congestion in the A6. If you are coming from the north, drive to Segovia and take road CL-601 towards La Granja and Puerto de Navacerrada.
When you reach the Puerto de Navacerrada, the biggest car park is placed east of the mountain pass(where the road to "Puerto de Cotos" starts)
By train:The puerto de Navacerrada is also reached by an old mountain train departing from Cercedilla. If you choose this option, you would have to take a train to Cercedilla (line C-8b) at Atocha Railway Station (Madrid) and connect to the trains to Puerto de Navacerrada.
By bus:Buses to Cercedilla can be caught (lines 684 and 684A) at the Moncloa underground station (Madrid), allowing for connections with the Puerto de Navacerrada as they stop by the railway station when they reach Cercedilla. There are also buses to Puerto de Navacerrada (line 691) leaving from Moncloa.
By plane:The closest major airport stands at Madrid-Barajas.
Your starting reference is the lower station of the chairlift leading east of the mountain pass. Look (it's easy) for that station and you will find by its side the beginning of a cement road leading uphill.