The most imposing structure in the town is the Bidar Fort. The Bidar Fort was built by Sultan Alla-Ud-Din Bahman of the Bahmani Dynasty., when his capital was moved from Gulbarga to Bidar in 1427 . The fort is a specimen of the Persian architectural style having a haphazard quadrangular layout surrounded by three miles long walls. Within the Fort Walls are 5 entrances(gates or darwazas), palaces (Gagan Mahal, Rangin Mahal and Takhat Mahal are more popular) and 2 mosues viz the Jami Masjid and the Solah Kambh Masjid, All these monuments and structures belong to the Bahamian era.
More about this vast Fort can be read below. Text courtesy: kaladarshana.com
Fortifications at Bidar date from the late 14th century when it became the capital of the later Bahmanis. Massive fort walls encompass the city as well as a citadel at the north. The citadel has spectacular gateways and ruins of palaces and mosques on a promontory that falls sharply to plains on the north and east. Recent excavations have shown that the palace area was in use from Chalukya times.
The south-east entrance to the fort has a sequence of three gates. The door with metal spikes on the left belongs to the first gate. The Sharza gate is next, so-called because of the sculpted basalt lions on the arched entrance. The parapet above this has a band of coloured tiles. A small dome above the Sharza Gate entrance has slender minarets and the parapet is crenellated. Several sets of unaligned stairs lead to platforms, guard rooms and balconies at various levels. A window on the right has a triple arch with a carved stone screens.
This innermost entrance gate has an imposing facade composed of a high, pointed arch. Above this is a crenellated parapet flanked by domed turrets. A large flattish dome rises behind this, an unusual feature for a fort entrance. The gravel path leading to it, flanked by battlements, traverses the inner moat.
The south walls of the fort that flank the Gumbad gate form a second inner layer of fortification. They are shielded by a moat composed of three rock-cut trenches, said to have had crocodile infested waters