Sistema Central

The Sistema Central, sometimes decsribed as the "dorsal spine" of Spain, is a geographical term referring to the chain of mountains splitting the Meseta Central into northern and southern regions, the former higher in elevation and smaller in area than the latter. The Sistema Central runs from east to west roughly along the southern border of the Spanish autonomous community of Castilla y León continuing into Portugal. It was formed more than 300 millions years ago during the late Palaeozoic, with further remodelling 275 million years ago.

The Sistema can be divided into two major ranges divided by the Rio Alberche: the Sierra de Gredos and the Sierra de Guadarrama. Much of the range is made up of water-holding granite, allowing springs to well up close to the summit, ensuring that together with snow melt the valley are green throughout the year. This area was one of the most southerly areas in Europe to be affected by glaciation during the last ice age, particularly in the Sierra de Gredos.

The Sistema Central is a geological term and local inhabitants generally prefer the names of the smaller ranges (highest mountain in brackets)

  • Serra da Estrela, Central Portugal (Estrela, 1.991 m)
  • Sierra de Gata, Cáceres + Salamanca (Peña de Francia, 1.732 m)
  • Sierra de Béjar, Cáceres + Salamanca (Canchal de la Ceja, 2.430 m)
  • Sierra de Gredos, Ávila, Toledo + Cáceres (pico del Moro Almanzor, 2.592 m)
  • Sierra de Guadarrama, Ávila, Madrid + Segovia (Peñalara, 2.430 m)
  • Somosierra, Segovia, Madrid + Guadalajara (pico del Lobo, 2.129 m)
  • Sierra de Ayllón, Segovia, Soria + Guadalajara (pico de la Buitrera, 2.046 m).

Highest mountain in the Sistema Central: Almanzor

Almanzor : Almanzor (2,592m) in the Sierra de Gredos is the highest mountain in Sistema Central and the province of Ávila . Formed during the Alpine Orogeny (mountian building), it formed principally of granite and so is not highly weathered.

The peak is also known as Moro Almanzor, from Al-Mansur ('the victorious'), the de facto Moorish ruler of Al-Andalus during the late 10th-early 11th centuries. His rule marked what was probably the peak of Islamic power in Spain . Legend has it that Al-Mansur passed by here after a terrible battle with the Christians. He was taken by the beauty of the mountains which at the time functioned as a frontier between Islamic Spain and the Christian North, and so he decided to set up camp for the night. Under the stars, he was captivated by the stories of shepherds from the area. They told him than in the heart of these mountains, terrible noises could be heard that would echo along the gulleys and ravines, and which would shake the very hearts of the people of these parts. The next day, the Moorish king bade the shepherds to lead him to the place they spoke of: a magnificent cirque in centre of the Gredos mountains. When the company reached the place, they were greeted by a deafening silence. Fearful of the King's reaction, they began to shout his name, which the duly returned amplified as an echo.

Only recommended for experienced climbers

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Sierra de Guadarrama

This short film in Spanish by the Madrid governement gives a publicity-style overview of the Sierra de Guadarrama.

The Sierra de Guadarrama from Wikipedia

The Sierra de Guadarrama is a mountain chain spanning half of the Sistema Central (a mountain system in the center of the Iberian Peninsula), located between the Sierra de Gredos in the province of Ávila, and Sierra de Ayllón in the province of Guadalajara. The range spreads in southwest - northeast direction, extending into the province of Madrid to the south, and towards the provinces of Ávila and Segovia to the north. The chain as a whole measures approximately 80 km in length, with its highest peak, Peñalara, reaching 2,430 m above sea level.

Peñalara (2430m) From wikipedia.

The vegetation of the mountain range is characterized by an abundance of pine forests and copses of oak and holm oak in its lower slopes, while the summits are dominated by shrub-filled pastures. The mountains abound with a variety of mammal life such as deer, roe deer and fallow deer, wild boar, badger, various types of weasel, European wild cat, fox and hare, among others. There are also a great variety of waterfowl species in the mountain lakes and reservoirs, as well as birds of prey such as the Eastern Imperial Eagle and the Eurasian Black Vulture.

The mountain range's proximity to Madrid has led to crowded conditions. The area is today crossed by numerous ports and railway routes and sustains a highly developed tourism infrastructure, coupled with provisions for various mountain sports; a state of affairs which is hazardous to the environment of the mountains making up the range.


With a length of about 80 km and extending in a southwestern-northeast direction, the mountains comprising the Guadarramas form a natural division between the North and South mesetas of the Iberian Peninsula as part of the Sistema Central. The mountain bases are located between the 900 and the 1,200 m above sea level, and the principal peaks of the range have an average topographical prominence of 1,000 m. The range's highest peak, Peñalara, reaches 2,430 m above sea level. The range begins in the valley of the Alberche river, which divides the Sierra de Gredos into two portions, and finishes in the Somosierra pass, which serves as the boundary between the hydrographic river basins of the Tagus and Duero rivers. The mountains contribute fluvial material to both rivers through the action of various mountain streams which meander throughout the range, such as the Jarama, Guadarrama and Manzanares which empty into the Tagus, and the Duratón, Cega and Eresma which flow into the Duero. The geographical coordinates of the range's northeast terminus are 41º 4' N 3º 44' W, and the southwestern end are is 40º 22' N 4º 18' W.

In addition to its main southwest - northeast alignment, the range has a westerly branch known as the Cuerda Larga or Carpetanos Mountains (Montes Carpetanos), although this name is sometimes also applied to the north part of the main spread between Peñalara and Somosierra. The Carpetanos section begins in the Community of Madrid, in Puerto de Navacerrada, has a length of 15 km and is an imposing arm of the range as it averages 2,000 m or higher in elevation until arriving at the Morcuera pass (Puerto de la Morcuera). From there, it slopes down until reaching the confluence of the Lozoya and Jarama rivers. The highest peak of the Cuerda Larga is the Cabezas de Hierro at 2,383 m.

Between Cuerda Larga and the main stretch of the Sierra de Guadarrama lies the Lozoya valley; one of the best mountain valley examples of the Sistema Central, which attracts numerous tourists in the winter for skiing- as well as in the summer for other distractions. Another western branch of the Guadarramas, La Mujer Muerta (The Dead Woman), or Sierra del Quintanar (Quintanar mountains), begins at the Port of Fuenfría (puerto de la Fuenfría}, and is located entirely in the province of Segovia. It has a length of 11 km and has several summits surpassing 2,000 m, among them, the Montón de Trigo (Wheat Pile).

In addition to the Cuerda Larga and the La Mujer Muerta, a series of small mountain and foothills are located at the periphery of the main mountains. Notably, in the Segovia area, there are: the cerro (hill) de las Cardosillas (1,635 m); cerro de Matabueyes (1,485 m); cerro del Caloco (1,565 m) and the Sierra de Ojos Albos (1,662 m); while in the Madrid area (from north to south), there are the cerro de San Pedro (1,423 m); Sierra del Hoyo (1,404 m); el cerro Cañal (1,331 m) and Las Machotas (1,466 m).

Notable Peaks of the Guadarramas

The peaks of Guadarrama have a relatively soft silhouette, with few peaks standing out as exceptionally larger than others in the chain. The most important and representative mountain peaks are set forth in boldface:Peñalara (2,430 m), the highest mountain of the Guadarramas;
Risco de los Claveles (2,387 m);
Cabezas de Hierro (2,383 m), highest of the Cuerda Larga;
Risco de los Pájaros (2,334 m);
Dos Hermanas (2,285 m);
Cerro de Valdemartín (2,280 m);
Bola del Mundo (2,265 m);
Pandasco (2,238 m);
La Maliciosa (2,227 m);
El Nevero (2,209 m); one of the most northern peaks in the mountain range;
Montón de Trigo (2,161 m);
Siete Picos (2,138 m);
La Najarra (2,108 m);
Flecha (2,078 m);
Peña del Águila (2,010 m);
La Peñota (1,945 m);
Monte Abanos (1,753 m); and
El Yelmo (1,717 m), the most important peak of la Pedriza.

Geology of the Sierra de Guadarrama

The Sierra de Guadarrama is the result of a clash between tectonic plates belonging to the South sub-plateau and the North sub-plateau, both part of the Iberian Peninsula's larger Meseta Central; (Central Plateau). The mountain range was formed during the Cenozoic era (starting 65.5 million years ago (mya)), although the predominant material of which the mountains are composed (granite shelf tableland) was preexisting, having been laid down during the Variscan orogeny during the Paleozoic era when the continental collision between Laurasia and Gondwana occurred to form Pangea. The mountains have undergone significant erosion since their formation, which is the reason why many peaks, especially in the northern and southern sections, have flattened summits (referred to by mountaineers as "cuerdas"). For these reasons, the material making up the Sierra de Guadarrama is of more ancient origin than many other well known mountain systems such as the Pyrenees, the Alps, the Andes and the Himalayas.

Formation detail
In the mid Paleozoic era (between 360 and 290 mya), an initial substratum of ancient granites and sediments started bending and metamorphizing, forming gneiss. Thereafter, approximately 290 and 250 mya during the Carboniferous period, the gneiss fractured, allowed a mass of magma to reach the surface which ultimately hardened into a granite shelf tableland. In the final phase of the Paleozoic era, during the Permian period, the tectonic plate collision causing the whole mountain range to rise. Finally, during the end of the Paleozoic through the Mesozoic era (between 250 and 65 mya) and up to the present, ongoing erosion processes reduced the size and smoothed and rounded the profile of the mountains of the Guadarramas.

It was also during this geologic era that an ocean shift took place causing the present day location of the mountains to be part of the ocean for a time (it is possible, in fact, that the then peak formations were only small islands barely rising above the level of the ocean). This accounts for the presences of limestone (a sedimentary rock formed predominantly from calcite derived from marine organisms) found in the rims of Guadaramma mountain peaks and in some of their interior caves. Limestone formations are evident at a number of the peaks— notably El Vellón, La Pinilla and Patones.

Other processes were at play during the Cenozoic era that shaped the present form of the Guadarammas. The erosion of the rocky massif provoked sedimentation which filled the mountain basins with sandstone. The action of glaciers during the Quaternary Period (1.8 mya up to the present) shaped several mountain profiles with small cirques, carved glacial lakes and left behind moraines. All three features can be found on Peñalara. Additionally, some traces of glacial passage are found in El Nevero and La Maliciosa in the form of sheepback-grooved rocks and small cirques. Finally, in the last million years, the action of glaciers caused consolidation of the network of rivers crisscrossing the mountain slopes, carved valleys and terraces resulting in the current appearance of the landscape.


Dam of Navacerrada.The climate of the Sierra de Guadarrama is marked by heavy precipitation which gives birth the the territory's numerous streams and rivers. There are several rivers of special relevance. The range's Segovia facing slopes give rise to the Moros and Eresma rivers, with the latter flowing through the City of Segovia. The Madrid facing slopes give rise to the Guadarrama river (from which the range and the town of Guadarrama takes their names), the Manzanares river, that passes by Madrid, and the Lozoya river, that passes by its namesake valley. On the South slope of the peak of Peñalara, at 2,200 m of elevation, there is a series of small, protected lakes of glacial origin.

Although the mountain range proper features a great number of dams, they are all of small volume. In the Segovia facing slopes, the more prominent dams are Peces, Revenga, Pontón and Pirón, while on the Madrid facing slopes are found the Tobar, Jarosa, Navacerrada and Pinilla. Outside the boundaries of the mountain range, in the Community of Madrid, there are three dams of much greater size: the Valmayor, Santillana and Pardo.

Flora and fauna

Flower growing in the high mountain areas of the Parque Natural de Peñalara.The flora and fauna of the Sierra de Guadarrama is made up of a great diversity of species that represent something of a synthesis between those that are common to the mediterranean landscape and climate of Spain's Centeal Plateau, and more specialized plants and animals native to in the high altitude climate and mountainous terrain of the Pyrenees and Alps.

The high slopes of the mountains are covered in Alpine grasses which are extensively used as grazing land for cattle. The meat that these cattle produce is of excellent quality and is specially denominated and certified as Ternera de Guadarrama ("Veal of Guadarrama"). Below the high mountain pastures, in the subalpine and mountainous flats, are some of the best natural Scots Pine (Pinus sylvestris) groves that exist in Spain.