The best time to trek is from 10 July to 15 August. The optimal time to set off for the lake from Saif ul Muluk is around 09:00 in the morning. Horses can also be hired from the Lake Saif ul Muluk along with a guide person who will take you to Ansoo Lake. The most difficult trek starts from Malka Parbat base camp where one have to climb on mountain by own feet without horse, here oxygen levels are very low so be very careful because it is difficult to breath. After some very difficult climb the next trek is bit easier to climb and from there scenes are heart touching, here temperature starts decreasing and you will feel cold so put on your jackets. Now you will start seeing ice and the whole next trek is ice covered, here you need sticks to walk and be very careful do not touch snow for a long time because you will get frostbite, now clouds are all around you and rain can start any time and temp can reduce to freeze you, put on glasses and hats and don’t stay here continue walking or riding on horses till you arrive the peek here you have to climb on yourself because the altitude is at the angle of 80 degree be very careful if you fall u die. After just 20 minutes climb on this most dangerous rocky trek finally you will reach at the height of 16,492 feet and there you will see ANSOO Lake, Mostly it is covered with clouds but some time clouds goes away and you will get chance to shoot it with your camera.
Another trek to reach Ansoo Lake is from Mahandri, which is 40 km below Naran Village, through Manor Galli and Kach Galli. This is a less trod route but nonetheless, a wonderful one to trek.
The name "Ansoo" comes from its tear-like shape (the Urdu word Ansoo means teardrop). The lake is said to have been discovered in 1993 by Pakistan Air Force pilots who were flying low above the area. Earlier, the lake was not even known to the locals.
Source: (wateen.net)