Issyk Kol is a lake where we stayed for a couple of days. It has several interesting features in my opinion. Here again I was surprised and wanted to find out more. It lies 1607 meters above sea level and is 180 km long and up to 60 km wide. It is deep, the deepest is 665 meters. These facts are not particularly interesting.
119 creeks and rivers flow towards the lake but only 49 actually reach it. The rest go into the ground and probably end up in the lake through the ground. Some of this water is probably heated to hot springs and enter the lake as the lake is warm and never freezes even in severe winter temperatures. No water flows out of the lake, if the level rises approx. 15 meters it will overflow. The water is slightly saline but only one sixth of ocean water.
The water level has changed several times. In prehistoric times (26 000-10 000BCE) it was higher than now and probably had a river going out. In the period 10000-300BCE it was 8-10 meters lower than today. They have found remnants of a big city 6-8 meters below the surface from that period. It must have been a big city and some acheologists call it a metropolis. They have found city walls 500 meters long and the populated area seems to have been several square kilometers. Scythian burial mounds have also been found. Then it was higher again for several centuries before it dropped and was lower in the period 1000-1300AD. A Nestorian cross on a rock dated 1312 is found in the lake.
Then in the period 1600-1800 it was higher than today and probably had a river flowing out. Now the level is dropping about 8 cm (3 inches) a year