The New Castle of Manzanares El Real is one of the absolute best day trips from Madrid, especially if you combine it with a hike among the waterfalls and rock formations of the nearby La Pedriza area. The castle itself dates back to the 15th century and was built by the Mendozas, one of the richest and most influential families in early Castile around the time of the reign of the Catholic Kings, Ferdinand and Isabella.
What stands out most about the castle is its amazing state of preservation (it was apparently restored in the early 20th century) and the decorative granite balls which circle the turrets and give the castle something of a fairy-tale look. Inside there is a small and underwhelming museum, but the €3.00 entrance fee is more than worth it just to visit the rooftop gallery with its decorative Gothic windows and amazing views of the Sierra de Guadarrama mountains, the Santillana Reservoir, and the city of Manzanares El Real itself.
El Parque Regional de Manzanares del Real es uno de los parques más grandes que encontramos en Madrid y en España, es un parque con muchísimas rutas desde la mayoría de sus accesos se puede subir al yelmo donde es muy bonito ver el atardecer.