The dominant feature of Spain is a great interior plateau known as the Meseta. It occupies roughly two-fifths of the country and lies generally about 1,500 to 4,000 feet (460 to 1,220 m) above sea level, dipping downward from east to west. Much of this vast tableland consists of dry, relatively flat terrain, though there are extensive areas of rough, eroded land. Deep valleys, canyons, and sharply rising mountains are also characteristic of the Meseta.
One of the principal mountain chains on the Meseta is formed by a series of ranges sometimes called the Cordillera Central. Its loftiest part, rising roughly 7,000 to 8,000 feet (2,130 to 2,440 m) above sea level, consists of the Sierra de Guadarrama, near Madrid, and the Sierra de Gredos, which crests at more than 8,500 feet (2,590 m). North of this central chain lies a basin containing the historic regions of Old Castile and Len; to the south are Extremadura and New Castile.
Virtually all sides of the plateau are bounded by mountains. Most prominent are the Cantabrian Mountains in the north, the Iberian Mountains in the northeast, and the steep Sierra Morena in the south. In the Cantabrian Mountains many peaks rise 5,000 to 8,000 feet (1,520 to 2,440 m) only a short distance from the ocean.
Beyond the Iberian Mountains, in the northeast, lies the wedge-shaped lowland basin of the Ebro River. It is cut off from the sea by a range of low coastal mountains and is flanked along the French border by the towering Pyrenees, which are geologically part of the rugged Alps system. The Pyrenees constitute Spain's most formidable range. Many of the craggy Pyrenees peaks rise to elevations of more than 10,000 feet (3,050 m). Pico de Aneto, the highest, reaches 11,168 feet (3,404 m) above sea level.
In the south of Spain lies another wedgeshaped basin—the lowland of Andalusia. Its broad base is along the Gulf of Cdiz; its sides are marked by mountains, mainly the Sierra Morena on the north and the Cordillera Penibtica on the south. The Penibtica chain runs along the Mediterranean coast and consists generally of low mountains. However, its chief range, the lofty Sierra Nevada, has the highest peak in mainland Spain—11,411-foot (3,478-m) Mulhacn. The highest peak in all of Spain is Pico de Teide in the Canary Islands, which reaches 12,172 feet (3,710 m).
Five major rivers drain Spain: the Duero, Tagus, Guadiana, Guadalquivir, and Ebro. None is exceptionally large, mainly because of the scant and erratic rainfall that occurs throughout most of Spain. Three of the rivers—the Duero, Tagus, and Guadiana—drain the Meseta. Each begins in the eastern part of the plateau and flows westward through Portugal to the Atlantic Ocean. In places their courses are marked by deep valleys, gorges, and canyons.
The Guadalquivir is the chief river of southern Spain. It meanders sluggishly through the Andalusian lowland, past Crdoba and Seville, and enters the Gulf of Cdiz after passing through a large marshy area known as Las Marismas. The Ebro River drains most of northeastern Spain. It begins in the Cantabrian Mountains, flows southeastward past Zaragoza, and enters the Mediterranean Sea by way of a narrow gap in the coastal mountains.
There are no large lakes in Spain. Many rivers and streams have been dammed, creating sizable but narrow reservoirs for irrigational and hydroelectric use.
The southern and eastern coasts of Spain lie within the region of Mediterranean climate, which is noted for bright sunny weather throughout most of the year. Summers are hot and dry; daily temperatures average 75 F. (24 C.). Winters are cool, with temperatures averaging about 45 F. (7 C.), and moderately rainy. The total precipitation, however, is relatively low, usually 15 to 25 inches (380 to 640 mm). Summers are especially hot in the Andalusian basin. Daytime temperatures there often reach 100 F. (38 C.).
Except in the mountains, summers on the Meseta are about as hot as those on the Mediterranean coast, but winters are considerably colder. In most areas temperatures dip to freezing or slightly below, and light snow falls occasionally. Rainfall is scant, usually less than 20 inches (510 mm) a year; most of it comes in spring and autumn.
Northern Spain lies in the path of westerly winds from the Atlantic, causing a rather cool, moderate climate the year round. There are no great temperature extremes as in the rest of Spain. Winter temperatures average 50 F. (10 C.); summer temperatures average 65 F. (18 C.). Rainfall is much more abundant.