Explanation:

 A man-made tank excavated by Ahom king Swargadeo Rudra Singha in memory of his mother Joymoti at Rangpur. Historical records reveal that the tank was constructed in 45 days at Rangpur in 1697. It is the largest man-made lake in India and stands on the area of 318 acres half of which is under water.
On the northern side of the tank, there are temples namely Kesavarai Visnu Dol or Joydol, Baidyanath Shiva Dol, Devi-Ghar, Sri Suryya Mandir, Ganesh Mandir and Ghanashyam Dol or Nati-Gosai Dol.