Description: History says, Raja Birat dug a big pond or dighi for the cows. The Dighi has many names such as Birat Dighi or Birna Dighi or Binna Dighi. After the independence of Bangladesh the Dighi was renamed as Nilsagar. Every year lot of visitors and different type of migratory birds come here. A Hindu temple situated on the east bank and an abode of a Muslim saint on the west bank of the Nilsagar.