Pamir is a range of mountains, part of which is in the Southern part of USSR, which is now Tajikistan, and which shares a border with Afghanistan. There are lakes in the mountains, and here are widescreen photos of three of those lakes. The traveller, Vladimir, says that these lakes have the names "Stinky", "High" and "Green". So this is the "Green" lake in the picture above. It actually becomes green under certain lighting conditions. An example is below:
At other times its more blue than green.
The photographer says it has a lot of fish in it.