Ganga Nuur is about 13km southeast of Dariganga. From the end of September until mid-October it is home to thousands of migrating swans. Along the shore, in a fenced compound, is delicious and safe spring water. If you don't fancy paying the car entry fee you can park by the gate and walk.
There are six lakes in the vicinity of Dariganga; all are part of the Ganga Nuur Nature Reserve, but apart from Ganga Nuur they are not really good for swimming, with boggy, muddy edges and plenty of reeds.