The Sierra de Hoyo enjoys a continentalized Mediterranean climate, influenced by altitude and orientation (characterized by cool winters (cold on the peaks) and hot summers, but much more pleasant than those of the southern plateau).

The Sierra de Hoyo serves as a natural barrier between the basins of the Manzanares and Guadarrama rivers, which form its eastern and western physical limits, respectively.

All these mountain formations have a lateral and isolated location with respect to the Guadarrama axis, from which they are separated by a series of fractures and faults, which run parallel to the main alignment.

The Sierra de Hoyo is distributed forming a sort of inverted arc, whose ends are guarded by the peaks of Navalospinos (1171 m) —to the northeast—, El Picazo (1268 m) ―to the south― and Peña Cardín (1130 m) —to the northwest—.

The Sierra de Hoyo is presided over by the peak/vertex of Estepar in the place or hill of La Mira, and is located at 1402.840 meters, the maximum altitude of the mountain chain.

Almost all of them dry up during the summer, except for the streams of Peregrinos (Guadarrama), or Trofas and Navahuerta (Manzanares), with water flowing throughout the year, which can be considered as its main fluvial currents.

The Manina and Trofas streams, on the other hand, originate on the southern slopes and flow into the Manzanares, after crossing Monte de El Pardo.

[4] This last stream forms the Gabriel Enríquez de la Orden reservoir, located in the foothills of the sierra, in the residential area of Los Peñascales (Torrelodones).

This is the main wetland in the mountain chain environment, along with the small reservoir of Los Rosales (around which extends the residential area Parquelagos, in Galapagar), which is supplied with water by the stream of La Pradera.

Corvids such as the iberian magpie, birds of prey such as booted eagles, buzzards, kites and griffon vultures join other species such as hoopoes and bee-eaters.

The latter includes two important urban areas (La Estación and El Pueblo), where almost 60,000 inhabitants live on a stable basis, to which must be added the floating population.

During the Andalusian period, the Sierra de Hoyo was part of the defensive system organized by the Muslim population to stop the advance of the Christian kingdoms.

La Torrecilla, in a ruinous state, is located on the maneuvering field of the Academy of the Corps of Engineers in Hoyo de Manzanares.

[10] In the municipality of Hoyo de Manzanares are the remains of some old movie sets, where many films were shot in the 1960s and 1970s, mainly Spaghetti Westerns (among them, A Fistful of Dollars).

Highest point and main summit Estepar (Hoyo de Manzanares) 1402,840 meters above sea level at the Permanent Station of the Port of Alicante (Geodesic Vertex).