Nobody was injured in the collapse, police said.
After the incident, the Bahu Fort Development Committee (BFDC) protested against the archaeology department and Jammu Development Authority, alleging that the wall collapsed due to lack of proper maintenance and renovation.
BFDC President Rajeev Charak said the 16th century fort was built by Maharaja Bahu Lochan and it was the birth place of Dogras.
The fort was a prime attraction for a number of tourists.
The vista of Himalayan Ranges and the Tawi river provide it perfect backdrop, he said.
He said the government had sanctioned a fund of Rs 69 lakh in 2010 to the archaeology department for renovation, and the department had sublet the work to JDA.