Derawar Fort is a large square fortress in Pakistan near Bahawalpur. The forty bastions of Derawar are visible for many miles in Cholistan Desert. The walls have a circumference of 1500 metres and stand up to thirty metres high.
The first fort on the site was built by Hindu Rajput, Rai Jajja Bhati of Jaisalmer. It remained in the hands of the royal family of Jaisalmer until captured and completely rebuilt by the nawabs of Bahawalpur in 1733. In 1747, the fort slipped from the hands of the Abbasis owing to Bahawal Khan's preoccupations at Shikarpur. Nawab Mubarak Khan took the stronghold back in 1804.
The nearby mosque was modelled after that in the Red Fort of Delhi. There is also a royal necropolis of the Abbasi family, which still owns the stronghold. The area is rich in archaeological artifacts associated with Ganweriwala, a vast but as-yet-unexcavated city of the Indus Valley Civilization.Wiki