Historical Alamgir Gate, Mandu, a part of the biggest fort in India - Madhya Pradesh

Alamgir gate, Mandu Fort, MP flicker.com

Alamgir gate, Mandu fort, MP commons.m.wikimedia.org
 Steeped in history, Mandu in  Madhya Pradesh has a spectacular but ruined citadel that is not easily accessible by the enemies, part of the reason being its location atop the high plateau.  Forming  an important military outpost by virtue of its strategic location  in an impressive  naturally-protected place  in the Vindhya hills surrounded by a ravine on all sides, every year it attracts tourists from India as well as abroad. The fort is 82 km in perimeter and is believed to be the biggest in India. What is so special about this big fort? Deep ravines cut into the sides of the 20 sq. km plateau (633 meters high)  occupied by the fort. The ruins are spread over an area of 21 sq. km. Besides its tough location,  mention may be made of the fort's high thick walls mostly consisting of small boulders, rubble, cobble, etc., stretch as far as  59.5 km (37 miles) long and the Narmada river blocking the way for the enemy's approach to the fort. Visitors can see  beautiful palaces, mosques, tombs, etc  amid the lush green gardens, lakes and woodland within the confines of  walls. Dilawar Khan Husain Ghuri (ruled 1401-5) had first redesigned the fort and begun the work and later Mahmud Shah I Khalji (ruled 1436-69) completed the work that had been left behind by the early builder.  It is an ancient stronghold as this region was prone to attacks from the Muslim rulers of NW of India.
Mandu, Madhya Pradesh, Alamgir gate. Flicker.com 

In 1902 Alamgir gate, Mandu Fort asibhopal.nic.in
Toward the end of the 10th century, Mandu became a prominent place under the Hindu ruling dynasty of  Paramaras  that controlled  the province of Malwa with their capital at Dhar. In 1305 the Sultans of the Delhi Sultanate  displaced the Hindu rulers. The Hindus were either killed or forced to become Muslims under threats to life.Alauddin Khaliji (c 1267- 4 Jan. 1316) was a notorious Muslim fanatic. He had his own father-in-law ruler Jalaluddin killed and paraded his head on a  spear in his camp to instill fear among his enemies In 1401 Dilawar Khan had a row with the Delhi sultanate and broke away from  it. He founded an independent sultanate with Mandu as the capital of the Malwa region.  Between 1405 and 1531, Mandu saw several developments such as palaces, gardens, lakes  etc., and it was the golden age of the new capital  and the fort was renamed  ‘Shadiabad’ (City of Joy). It was during this period there was an infusion of Islamic architecture characterized by elegance  and simplicity. This gave rise to Mogul architecture with fusion of Hindu building style as in Delhi and Agra. 

Alamgir gate, Mandu fort, MP lonelyplanet.com
What the visitors see here at Mandu are the the remnants of 12  gates of the great fort, of them, only  seven survived as of today.  Located at vantage points, the soldiers from these gates were guarding the  place 24 hours a day, on the look of the sign of any approaching column of an enemy's army. Through a system of acoustics, I believe, they will inform the palace  and other gates of the approaching danger.  Designed in such a way, the  soldiers  could see  at long distances, looking for any  movements

 The barbican in front of Alamgir  gate  has  a walled enclosure with two square bastions built at flanks. The height of the  arched building from the bottom level to the top of the Kanguras is 11 m. The covered passage is about 9.5 m x 4 m. and there are four arches. The three inner ones support barrel-shaped roof. The outer  portion of the building  is characteristic of  a flat roof, covered with slabs. The architecture of  the gateway is  as simple as it it can be, but for a band of carved masonry along piers of the outer arch of some parts. It is a conventional design.  
 Mandu is 35 km from Dhar and 100 km from Indore, MP.

Tit-bits: 
Alamgir gate, Mandu bl.uk/onlinegallery

''Photo the Alamgir Gate at Mandu, Madhya Pradesh, taken by an unknown photographer in c.1902. The Alamgir Gate is one of a series of fortified gateways on the approach to the Delhi Gate, the main entrance to Mandu at its northern tip. It is an arched Islamic masonry structure crowned with spearhead battlements.  Its walls are 59.5 km (37 miles) long and were begun by Dilawar Khan Husain Ghuri (ruled 1401-5) and completed by Mahmud Shah I Khalji (ruled 1436-69). An ancient stronghold, Mandu first came to prominence under the Paramara dynasty (who ruled the province of Malwa with their capital at Dhar) at the end of the 10th century, and remained under Hindu rule until 1305 when it was conquered by the Sultans of Delhi. In 1401 Dilawar Khan broke away from Delhi and established an independent sultanate. Mandu's golden age came as the state capital of the Sultans of Malwa between 1405 and 1531. They renamed the fort ‘Shadiabad’ (City of Joy) and built palaces, mosques and tombs amid the gardens, lakes and woodland within its walls. Most of the remaining buildings date from this period. They constitute an important provincial style of Islamic architecture characterised by an elegant and powerful simplicity that is believed to have influenced later Mughal architecture at Agra and Delhi''. From: (http://www.bl.uk/onlinegallery/onlineex/apac/photocoll/a/019pho000430s32u00031000.html)