Purana Quila

the Old Fort or the
Purana Quila is a good example of medieval military architecture.
Built by the Mughal Emperor Humayun, with later-day modifications
by Sher Shah Suri, the Purana Quila is a monument of bold design,
which is strong, straightforward and every inch a fortress. The
Qal'a-I-Kunha Masjid and the Sher Mandal are two important
monuments inside the fort.
Though not many buildings within the crumbling walls of the
Purana Quila have survived, there are two monuments of
architectural importance within it that have survived the ravages
of time: the Qal'a-I-Kunha Masjid and the Sher Mandal. Both these
monuments were built by Sher Shah Suri.
The Qal'a-I-Kunha Masjid is a superb but austere building, with
sparse, sophisticated ornamentation in sandstone and a little
marble. This mosque belongs to the Indo-Islamic style of
architecture. It has a single dome, which is not pronounced and
lacks the grandeur of the bulbous onion-shaped domes generally
seen on Islamic buildings.
Even today, the Lal Quila is an eloquent reminder of the glory of
the Mughal era and its magnificence leaves many wonder-struck and
breathless. It is still a calm haven of peace which helps one to
break away from the frantic pace of life outside the walls of the
Fort and transports the visitor to another era of time.