The Sierra de Guadarrama (Guadarrama Mountains) is a mountain range forming the main eastern section of the Sistema Central, the system of mountain ranges along the centre of the Iberian Peninsula. It is in Spain, between the systems Sierra de Gredos in the province of Ávila, and Sierra de Ayllón in the province of Guadalajara.
The range runs southwest–northeast, extending from the province of Ávila in the southwest, through the Community of Madrid, to the province of Segovia in the northeast. The range measures approximately in length. Its highest peak is Peñalara, in elevation.
The flora of the Sierra de Guadarrama is characterized by the higher elevation Atlantic vegetation region with Juniper groves, montane grasslands, Spanish broom thickets, pine forests, and Pyrenean oaks forests; and in the lower elevation Mediterranean vegetation region by Holm oak forests, while the pastures around the summits are fringed by juniper and Spanish broom shrubs. The mountains abound with a variety of wildlife such as Iberian ibex, roe deer, fallow deer, wild boar, badger, various types of weasel, European wild cat, fox and hare. The area is also rich in birdlife, including birds of prey such as the Spanish imperial eagle and the Eurasian black vulture.
The mountain range's proximity to Madrid means it can get crowded with visitors. The range is crossed by numerous roads and railway routes. It has a highly developed tourism infrastructure, coupled with provisions for various mountain sports. This poses a threat to the fragile environment and habitats of the mountains.
Description
Etymology of the name The name, (Guadarrama Mountains), is taken from the Guadarrama River and the town of Guadarrama, both of which are located in these mountains. The word Guadarrama itself is derived from the Arabic words for 'sandy river' — composed of guad (from , meaning 'river') and arrama (from , meaning 'sandy').
Another interpretation considers unlikely that a minor river could design a vast mountain range, and makes the name derive from the Latin , meaning 'water divide', which very aptly describes the position of the sierra between the two largest water basins in the Iberian Peninsula, those of the Douro, to the north, and of the Tagus, to the south.
In the Middle Ages, this mountain range was called ('dragon range') because of the profile of Siete Picos mountain.
General information The Guadarramas form a natural division between the North and South mesetas of the Iberian Peninsula, part of the so-called Sistema Central.
The mountain bases are located between 900 and 1,200 metres above sea level, and the principal peaks of the range have an average topographic prominence of 1,000 metres. The range's highest peak, Peñalara, reaches 2,428 metres above sea level. The range begins in the valley of the Alberche river, which divides the Sierra de Gredos into two portions, and finishes at the Somosierra Pass, which serves as the hydrographic boundary between the river basins of the Tagus and Douro rivers. The mountains contribute fluvial material to both rivers through the action of various mountain streams, 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 lies near 41° 4' North, 3° 44' West, and the southwestern end near 40° 22' North, 4° 18' West.
Diverging from its main southwest-to-northeast alignment, the range has a westward-trending branch: the ("Long Rope"), or Carpetanos Mountains (Montes Carpetanos). (This name is sometimes also applied to the northern part of the main axis of the Guadarramas between Peñalara and Somosierra.) The 15 km long Carpetanos sub-range is an imposing sight, starting in the Community of Madrid at Navacerrada Pass, and averaging more than 2,000 metres in elevation all the way to the Morcuera Pass (). From there, the Carpetanos slope downward until they reach the confluence of the Lozoya and Jarama rivers. The highest peak of the Cuerda Larga is the Cabezas de Hierro at 2,383 metres.
Between Cuerda Larga and the main extent of the Sierra de Guadarrama lies the Lozoya valley, one of the most picturesque mountain valleys of the Sistema Central, which attracts numerous tourists in the winter for skiing, as well as in the summer for other diversions. Another western branch of the Guadarramas, ("The Dead Woman"), or (Quintanar Mountains), begins at the Fuenfría Pass (Puerto de la Fuenfría), and is located entirely in the province of Segovia. It is 11 km long and has several summits surpassing 2,000 metres, among them, the Montón de Trigo ("Wheat Pile").
In addition to the and , a series of small mountains or foothills are located on the periphery of the main range. Notably, in the Segovia area, there are the Cerro (hill) de las Cardosillas (1,635 m, 5,364 ft), the Cerro de Matabueyes (1,485 m, 4,872 ft), the Cerro del Caloco (1,565 m, 5,134 ft), and the Sierra de Ojos Albos (1,662 m, 5,452 ft); and, in the Madrid area (from north to south), there are the Cerro de San Pedro (1,423 m, 4,668 ft), the Sierra del Hoyo (1,404 m, 4,606 ft), the Cerro Cañal (1,331 m, 4,366 ft), and Las Machotas (1,466 m, 4,809 ft).
Notable peaks The peaks of Guadarrama have a relatively soft silhouette, with few standing out as exceptionally larger than others in the chain: Monte Abantos (1,753 m, 5,751 ft) Bola del Mundo (2,265 m, 7,431 ft) Cabezas de Hierro (2,383 m, 7,818 ft), highest of the Cuerda Larga Dos Hermanas (2,285 m, 7,496 ft) Flecha (2,078 m, 6,807 ft) La Maliciosa (2,227 m, 7,306 ft) La Najarra (2,108 m, 6,916 ft) El Nevero (2,209 m, 7,227 ft); one of the most northern peaks in the mountain range Pandasco (2,238 m, 7,342 ft) Peña del Águila (2,010 m, 6,594 ft) Peñalara (2,428 m, 7,965 ft), the highest mountain of the Guadarramas La Peñota (1,945 m, 6,381 ft) Risco de los Claveles (2,387 m, 7,831 ft) Risco de los Pájaros (2,334 m, 7,657 ft) Siete Picos (2,138 m, 7,014 ft) Montón de Trigo (2,161 m, 7,089 ft) Cerro de Valdemartín (2,280 m, 7,480 ft) El Yelmo (1,717 m, 5,633 ft), the most important peak of La Pedriza
Geology
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 66 million years ago), 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 Pangaea. 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, called "cuerdas" by mountaineers. 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 that the then-peak formations were only small islands, barely rising above the level of the ocean. This accounts for the presence of limestone (a sedimentary rock formed predominately 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 in play during the Cenozoic era that shaped the present form of the Guadarramas. 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.
Principal cities and towns The Sierra de Guadarrama is surrounded by prominent population centres, which feature many second residences, occupied during holiday periods. The population pressure on and nearby the southeast slopes of the mountains near the Community of Madrid is very high, motivated partly by the large quantity of people who wish to live near the mountains. The most important cities are San Lorenzo de El Escorial, Guadarrama, Navacerrada, Cercedilla, Manzanares el Real, Miraflores de la Sierra and Rascafría in the Community of Madrid, and Los Ángeles de San Rafael and San Ildefonso in the province of Segovia. These towns are departure points for accessing the nearby mountain slopes and function as a centre of the tourism trade providing lodgings, restaurants and stores for visitors. Although these municipalities are located at the feet of the mountains, they are situated below 1,200 meters. The Sierra de Guadarrama serves as backdrop for the cities of Madrid and Segovia, although Segovia is located closer to the peaks than is Madrid.
Places of interest
The Sierra de Guadarrama has a series of valleys and zones which are of special interest from both an aesthetic and ecological viewpoint. Due to the proximity of Madrid's metropolitan area to the Guadarramas, many such special interest zones are host to a large number of mountain climbers and general interest tourists the year round. The most heavily visited areas are the Parque Natural de Peñalara (Peñalara Natural Park) and La Pedriza, an unusual mountain formation.
Valle (valley) de la FuenfríaAn eastern valley in Cercedilla, the Community of Madrid, featuring one of the better preserved wild pine forests of the mountains. The valleys faces in a north to south direction, has a length of approximately 5 km, a width of approximately 2 km and is located between Siete Picos and the edge of the province of Segovia. The valley's dense forest features a deep creek and a well-preserved, ancient Roman road that crosses the mountain running toward the Fuenfría Pass. On weekends and holidays the valley is flooded with tourists and mountain climbers who debark at a recreation area with a car park at the valley's lower edge.
Valle de Valsaín