Sevan is one of the three large lakes in the Armenian highland.
In ancient times it was called Gegharkunik or Geghama Sea. Sevan is the largest lake in Caucasus as well as one on the largest and highest freshwater lakes of the world.
The lake surface is at an altitude of 1897 m above sea level. Its depth is 80 m, an area - 1260 km2, length - 70 km, width - 55 km and the volume is 58 billion cubic metres.
In summer, the middle temperature of lake surface is 18 - 23 degrees above zero. In winter the lake is partly covered with ice.
Sevan consists of two unequal parts - Big Sevan and Small Sevan. These parts are merged by 5th km length strait which is located between the peninsulas of Artanish and Noradus. The southern and eastern shores are broad and smooth, while the northern and north - eastern shores are narrow and rocky.
The Lake, on the west side, is surrounded by Geghama, from the north - Aregunyats, from the east - Sevan and from the South - Vardenis mountains.
Sevan is fed by 28 rivers of which Gavaraget, Argithci, Martuni, Karthcaghbyur, Masrik, Dzknaget are the most famous.
The Lake Sevan has tectonic, volcanic origin. From the geological point of view the Great Sevan is an ancient, intermountain concavity, where there was a water basin in the remote past. A separate lake has been existed as well in the place of the Small Sevan.
Young volcanic lava - stream raised the water level blocking the exit of the Small Sevan. Then Big and Small Sevan assembled into the current Sevan. In the northern part of the lake the island of Sevan is situated which has become a peninsula by artificially making water level low. The lake has a good impact on the surrounding area and preserves the natural equilibrium of the entire basin. The water as well as the fish reserves are of great economic importance. Most of the canals irrigating the Ararat valley as well as the whole 6 electric power stations of cascade of Hrazdan are supplied by the water of Sevan.
In the middle of 20th century people by their interference had violated the natural condition of lake. Sevan-Hrazdan irrigable and power complex was built. Due to the deepening of the source of the river Hrazdan, the part of water supplies had been released. The water level dropped up to 19 m and the area decreased up to 12%.
An opportunity appears in the place of liberated areas to build a railway and highway passing through the north - eastern cost.
New changes were made in water balance to make it possible for the construction of water - piping Arpa - Sevan tunnel, with length of 48,3 km. Sevan National park was created for solving environmental problems.
Sevan is of great importance from the view of tourism. Around the coast there are many ‘cyclopean’ fortresses relating to the Bronze Age (Lcashen, Hayravanq). Archaeological research has shown that 3500 years ago the substantial part of Sevan was occupied by land. There were populated areas where the population was engaged in farming and cattle - breeding.
A lot of buildings of Urartu Kingdom (Velikukhi, rock inscription of Rusa) and medieval architectural monuments (Sevanavanq, Hayravanq and etc.) were preserved.
In the history of Armenian people many significant events are associated with the Lake Sevan. In the historical novel ‘Gevorg Marzpetuni’ by Muratsan, in chapter ‘Tzovamart’ the battle of Sevan against the Arab invasion was described.
In autumn the huge clouds descending from the peaks of high mountains into the water surface make a striking sight. In sunny weather the Lake Sevan flabbergasts with its iridescent shades of blue but in cloudy weather the clear blue turns into a hard metal. Sevan seems to be a piece of heaven on the earth. Sevan is the pearl of Armenia nature.