Hermanos de Colmenarejo SL (tel. 91-314-64-08) runs regularly from the Plaza Castilla Intercambiador station. The journey lasts about an hour (Rte. 724).
If you're driving, take the M-607 to Cerceda, and then swing right on to the M-608, which brings you straight to Manzanares.
The Town Hall, Plaza del Pueblo 1 (tel. 91-853-00-09), will give you full information on the town and its castle. There is also a small information kiosk at the entrance to the castle. Also see the website www.manzanareselreal.org.