The Gunfoundry also known as Top ka Sancha (1783 AD) was a cannonball factory set up by the second Nizam of Hyderabad, Nawab Mir Nizam Ali Khan at Fateh Maidan in Hyderabad, India.

The historic Aliya High School for Boys and Mehboobia College for Girls, both are opposite to Gunfoundry, across the main road that leads to Abids (in south).

[clarification needed] The Gunfoundry was one of the several cannon and cannonball factories set up in 1786 AD by French general Michel Raymond who was in the service of Nawab Mir Nizam Ali Khan, the second Nizam of Hyderabad.

Due to poor maintenance, the tapered walls were reduced to 25 to 30 feet.

In the lower portions, brick arches were made in semi-circular shape, where the smelting was carried out under the supervision of General Raymond.