Suraj Tal or Suraj Tal Lake also called Surya taal, is a sacred body of water, literally means the Lake of the Sun God, and lies just below the Bara-lacha-la pass (4,890m) (8 km (5.0 mi) in length) in the Lahaul and Spiti valley of Himachal Pradesh state in India and is the third highest lake in India, and the 21st-highest in the world.
Suraj Tal Lake is the source of Bhaga River which joins the Chandra River downstream at Tandi to form the Chandrabhaga River in Himachal Pradesh territory, and as it enters Jammu and Kashmir it is renamed as the Chenab River. The Bhaga River (a tributary of the Chandrabhaga or Chenab) originates from Surya taal. The other major tributary of the Chandrabhaga, the Chandra originates from the glacier close to the Chandra Taal lake in the Spit idistrict.
Terrain: The lake is fed from the glaciers and torrential nullahs (streams) originating from the Bara-lacha-la pass, which is 8 km (5.0 mi) long and is also called the "Pass with crossroads on summit" since roads from Zanskar, Ladakh, Spiti and Lahaul meet at this pass. In addition to the Suraj Tal and the Bhaga River that originates from it, Bara-lacha-la Pass is also the source of the Chandra and Yunan Rivers in the northwest and north, respectively. The lake is situated in the Upper Himalayan Zone or High Latitudinal Zone part of the Himalayas which has very sparse population with climatic conditions akin to polar conditions. Snowfall in this zone, though scanty, is reported to be spread all round the year. Rainfall precipitation is rare in the region.
Geology: The Lake's geology is represented by the Bara-lacha-la Pass, which is reported to be an early rifting event on the northern Indian passive margin and that the Basalts which are emplaced along the trans–tensional faults indicate that.
Bhaga Valley: The Bhaga Valley (Tod or Stod Valley) formed from Suraj Tal up to Tandi, the confluence point with Chandra River, is 64 km (39.8 mi) long. The valley, which is a narrow gorge, is devoid of any vegetation up to Darcha and thereafter it widens up to its confluence with Chandra River at Tandi with terraces between Darcha and Tandi which are under cultivation in the lower slopes, with the middle slopes having grasslands. Plantation of trees and shrubs to meet fuel wood and fodder requirements have been done on the hill slopes.
Lahaul Spiti valley is common a destination for Indian and foreign tourists for road trips, trekking and motorcycling which cover the Lake and the Bara-lacha-la pass, en route from Manali to Leh.
Trekking: Trekking tours are a common feature. One such trek route is the Zingzingbar–Suraj Tal–Bara-lacha-la, which involves trek along the Bhaga River for 3 km (1.9 mi), cross a bridge to the North bank, then a further climb of 2.5 km (1.6 mi) from the bridge followed by a steep foot trail up to Suraj Tal.
Biking tours : Motorcycle trips during the season when the area is approachable are undertaken by tourists. During such trips from Manali to Leh, the section between Patseo to Bara-lacha-la is a rough journey of 30 km (18.6 mi). Along this route, two small lakes, the Deepak Tal and the Suraj Tal are seen.