About 400m south-east of the flagstaff tower lies the
Chauburji-Masjid, a double-storeyed structure with a central chamber
surrounded by a small chamber on each side. There is a 'minhrab' or prayer
niche, in the west wall of the western chamber.
The upper storey of the mosque is occupied by a domed chamber on the
southwest corner, other such chambers having disappeared. It drives its
name, meaning the 'mosque with four towers', from its original four domes.
It was repaired and altered in the late Mughal times.
It was built by Feroze Shah Tughluq, evidently as a mausoleum and
probably formed part of his palace called Kuskh-i-Shikar or
Kushk-i-Jahan-Numa by contemporary writers. Another surviving part of his
palace situated over here is Pir-Ghaib
.