In the last decades of the 19th century, a small and selected scientists and intellectuals group, induced by a research and exploration spirit, developed the first cartographic, geologic, botanic and fauna studies related to the Sierra de Guadarrama. That trend of scientific interest came together in 1876 with the emergence of a pedagogic renewal movement, impelling the Sierra knowledge and love: The Free Education Institution (La Institución Libre de Enseñanza).
At the early 20th century, the first sports and mountaineers societies emerged, such as The Royal Spanish Peñalara Alpinism Society, the first institution to ask for the Sierra to be declared a National Park, in the 20’s decade. But not until the 1930 decade started the Sierra protection with, for example, the implementation of the Environmental Status of Natural Site of National Interest to the Height, Peñalara Cirque and Lakes, La Pedriza de Manzanares and the Acebeda Pinewood. (Sitio Natural de Interés Nacional, Cumbre, Circo y Lagunas de Peñalara, La Pedriza de Manzanares y el Pinar de la Acebeda).
Later on some of those protected areas were reclassified, and other Environmental Status came, national and from the European Union, exceeding the National Park limits. Finally, on June 25th 2013, The National Parliament (Congreso de los Diputados) approved the Bill declaring the Sierra de Guadarrama a National Park.