According to the legend the sound of the firing of this cannon used to effect the pregnant women living within the distance of 2 Kos (1 Kos= appro. 3 kilometers) of the Fort, as a result of which caused an abortion.
According to the history of Nepal, The Kalitop was brought to the Fort from Kathmandu three hundred years ago in the period of King Prithivi Narayan Sah, the leader of unification of Nepal. Consisting of two iron wheels, the cannon needs nine kilogram of gunpowder, cow dung and green leaves for one fire. To put those materials inside the barrel a long iron stick is also kept near it. In the year 2015 BS a troop of national army with 30 soldiers tried to take "The Kalitop" to Kathmandu but they couldn't succeed.