With the Joydol, Shivadol and Devidol temples on its banks, the Joysagar Tank was built by Ahom King Rudra Singha in memory of his mother Joymoti at Rangpur in 1697. Joymoti, who sacrificed her life to save her husband Gadapani is considered a patriotic martyr and is a legend in Assam history. The tank covers an area of 318 acres.