A country of altitude made of rock...
Consubstantial with that of the Pyrenean massif, the orogeny (set of mechanisms for the formation of mountains) of Andorra probably took place around forty million years ago, when the Eurasian and Iberian tectonic plates collided. The area occupied by the current Andorran territory is located in the heart of the Pyrenees, and during this geological collision, it was subjected to very intense folding of the earth's crust. However, the wide variety of rock formations that can be identified throughout the territory were already present before this great tectonic shock. It simply brought to the surface a mixed compound of slate and schist in the northwest, tapered reliefs made of gneiss in the northeast and an imposing granitic massif in the southeast. Another notable geological fact is that the erosion of glaciers (whose formation dates back to the Quaternary era, between 2.6 and 1.5 million years ago) is the main cause of Andorra's current geological profile. These would have slid along the major valleys of the principality, shaping the valleys themselves, but also the Andorran cirques and lakes. Andorra's main river, the Valira (flowing towards Spain and leaving Andorra at its lowest point, at an altitude of 840 m), continues to shape the territory today in three deeply cut valleys forming a "Y" and at the heart of which is concentrated most human activity. Located on the southern slope of the Pyrenean massif, the average altitude (1,996 metres) of the territory makes it the highest country in Europe, and its capital Andorra la Vella (1,013 metres) the highest capital on the continent! There are no less than sixty-five peaks exceeding 2,500 metres in altitude, with the highest point being the Coma Pedrosa peak, located on the western side of the country (along the Spanish border) and rising to 2,942 metres. Right next to it is the Roca Entravessada, the second highest peak in the country, as well as the Sanfonts and Port Nègre peaks. In the eastern part of Andorra are the peaks of Envalira and Portelleta, while the peaks of Casamanya and Estanyó, which form a natural border between the valleys of Valira del Nord and Valira d'Orient, are found in the north. Finally, the north of the country is made up of the peak of Médécourbe and its eastern neighbours, the peaks of Tristagne, Font Blanca, la Serrera and la Cabaneta. If for centuries Andorra's geographical confinement and the inhospitable nature of its mountainous terrain have kept it in deep isolation, they are nowadays the main reasons for visitors to the country: what once discouraged them has become a real tourist attraction, thanks to the installation of first-class ski resorts. However, it should be pointed out that, despite the use of avalanche control devices or explosives, avalanches do occur in Andorra, especially from February to May. Other geographically related risks include frequent landslides and rock falls, which occur after heavy rainfall, and earthquakes, which are generally too small to be felt, but are a natural hazard that is difficult to predict.
... and water
From a hydrographic point of view, with the exception of the Solana, whose waters flow into the Ariege basin, Andorra lies entirely within the Valira basin, which covers the whole of the country to within 30 km². As a result, the Principality has the peculiarity of straddling the divide between the waters of the Mediterranean and those of the Atlantic, represented by the hydrological systems of the Ebro and Garonne respectively. In fact, water is present everywhere in Andorra. The country is dotted with high altitude lakes and ponds (about sixty in all, of glacial origin), including the lake of Juclà (particularly popular with hikers in the summer months, its surface area of 21.3 hectares making it the largest in the principality), which gives it a substantial river network. We should also mention the cirque and lakes of Pessons, which form a landscape that is well worth a visit: the cirque, a granite glacier, is surrounded by peaks of almost 2,800 metres in altitude. It is breathtaking. The Gran Valira, the most important river in the Principality, is formed in Escaldes-Engordany, where the Valira d'Orient (from the Pessón lakes, it irrigates the valleys of Soldeu, Canillo and Encamp) and the Valira del Norte (born from the Tristaina lakes before irrigating the valleys of Ordino and La Massana) meet. Together with its tributaries, this river divides Andorra into three valleys, giving the principality its characteristic Y shape. Its course has strongly influenced road communications and territorial development. Although river overflows can cause potentially destructive floods (as was the case on the Spanish-Andorran border in 2008), cases are rare. Water is one of Andorra's major natural resources, thanks to the hydroelectric power station at Lake Engolasters: the Les Escaldes dam produces hydroelectric power that covers nearly 20% of the country's needs. Taking advantage of the curative virtues of the thermal spring of Les Escaldes, the Caldea balneotherapy centre (the largest in Europe in the mountains) attracts an impressive number of visitors. The purity of the water in the mountains also allows a large part of the Andorran population to be supplied with drinking water. It is also used for fishing and to irrigate the principality's various crops, especially tobacco. Among other natural resources, Andorra's forests, which cover a large part of the territory, provide a good source of wood (and also present a risk of fire, although none has ever proved fatal), and Andorra's subsoil contains important deposits of iron and lead.
