Ichnussa

The Romans called the island Sardinia, however the origin of this name is uncertain. The Greeks named it Ichnussa after its footprint shape. One theory is that the name is a deviation of Sardo, a mythical commander who conquered the island at the head of a group of Libyans.
Sardinia is 270 km long and 120 km wide. The four extreme points are Capo Falcone in the north, Capo Teulada in the south, Capo Comino in the east and Capo Argentiera in the west. There are four gulfs on each side of the island: the gulf of Asinara in the north, the gulf of Cagliari in the south, the gulf of Orosei in the east and the gulf of Oristano in the west.
The coast of Sardinia is approximately 1400 km long; the eastern and northern coasts mainly consist of tall rocky cliffs. In the gulf of Orosei the cliffs are over 400 metres tall. Near the head of Monte Santo they reach 757 metres in height. The southern and western coasts are predominantly sandy beaches with dunes. Immediately to the south of the Gulf of Orosei, on the gulf of Arbatax, is the location of the famous red cliffs of Porfido.
Many caves exist around the coast of Sardinia, situated off deep inlets, formed from now submerged ancient river valleys called 'coste a rias'. The majority of these are on the north eastern coast, the Gallura region.
The mountains of Sardinia are very ancient, and different from every other mountainous Italian region. The rocks which the island is made of emerged before the Alps and the Apennines.
Sardinia has several mountain ranges; none are more than two thousand meters high as a result of tens of millions of years of erosion. The northern part of Sardinia has several mountain ranges. The highest is the Gennargentu that reaches 1834 metres (peak La Marmora). The other mountain ranges are the Marghine-Goceano and the mountains of Alà that reach around 1200 metres in height. The most northerly and isolated is the granite range of the Limbara (1362 metres).
The largest mountain ranges in the southern part of the island are separated by the lowland of the Campidano. The range of the Iglesiente is situated on the western side of the plain (peak Linas mountain 1236 metres), to the east a range that reaches 1069 metres with the peak of Serpeddì. When an ancient arm of the sea filled up the lowlands of the Campidano was formed, this has an area of about 2000 square kilometres. It extends from the north west to the south east of the whole southern centre of Sardinia, creating a corridor between the gulf of Oristano and the gulf of Cagliari. In the extreme north west of the island between the gulf of the Asinara and that of Alghero, a similar but smaller lowland of the Nurra was created in the same way.
The irregular distribution of the mountain ranges is the cause of the island's fragmented hydro-graphy, the lack of large rivers, and the nature of the ground. Much of the ground is impermeable which prevents the formation of underground water sources. This, coupled with rains in only a few periods of the year, makes the regime of the water courses strongly variable. All Sardinian rivers are torrential in nature, with high flows in the spring contrasted with low flows in summer.
The island has three rivers of note: the Tirso (150 km in length with a 3100 square kilometre hydrographic basin), the Flumendosa and the Coghinas. The source of the Fluemendosa is from the Gennargentu mountain range. It flows in a southerly direction for 127 km, after being blocked with dykes in several places it flows towards out to the south coast of the island. The Coghinas is 123 km in length, its source is in the mountains of Alà, it flows in a north western direction forming a 17 km² artificial lake. Finally it flows into the gulf of Asinara.