NilsagarNilsagar is a popular historical dighi (big pond). It is located at Gorgram union about fourteen kilometer south-west of Nilphamari district proper. During the time of Raja Birat there were lot of cow farms at Gorgram union. Raja Birat dug a big pond or dighi for the cows. There many name such as Birat Dighi or Birna Dighi or Binna Dighi. After the independence of Bangladesh the dighi was renamed as Nilsagar .
The total area of the dighi (big pond) is 21.449 ha. The Nilsagar dighi is encompassed by walls. The main embellished Front door of the dighi was established by Raja Birat. Every year the banks of the dighi are used as a village fair during the month of Baisakh. Every year lot of visitors and different type of migratory birds come here. Nilsagar is familiar as a recreation zone. A Hindu temple situated on the east bank and an abode of a Muslim saint on the west bank of the Nilsagar.