khiljiThe Alai Darwaza is the maingatewayfrom southern side of the Quwwat-ul-Islam Mosque. It was built by the secondKhiljiSultan of Delhi,Ala-ud-din Khiljiin 1311 AD, who also added a court to the pillared to the eastern side. Thedomedgateway is decorated with redsandstoneand inlaid white marble decorations, inscriptions inNaskh script, latticed stone screens and showcases the remarkable craftsmanship of the Turkic artisans who worked on it. This is the first building in India to employIslamic architectureprinciples in its construction and ornamentation.[3]TheSlave dynastydid not employ trueIslamic architecturestyles and used false domes and false arches. This makes the Alai Darwaza, the earliest example of first true arches and true domes in India.[10]It is considered to be one of the most important buildings built in theDelhi sultanateperiod. With its pointed arches and spearhead of fringes, identified as lotus buds, it adds grace to the Quwwat-ul-Islam mosque to which it served as an entrance

lodiThe tomb of Sultan Sikandar Lodi has a striking appearance, for it is decorated with enameled tiles of various colors. The most important structural feature of the tomb is the double dome, which was designed to preserve the symmetry and relative proportions of the body of the building. This feature was probably borrowed from Iran. Its first traces can be found in the tomb of Shihab-ud-din Taj Khan (1501 A.D.), locally called Bagh-i-Alam Ka Gumbad. This innovation played an important part in the evolution of the Mughal style. tughlaqbuilt exquisitely in an irregular polygon shape within a rectangular shaped three rubble walled enclosures with its eastern side aligned absolutely straight to overlook the Yamuna River. This fourth Palace was built next to the river banks due to shortage of water in the other three places where the Sultan had three more Palaces.The central portion lying within the three enclosures of Feroz Shah Kotla citadel is known to be the largest and was named after the Sultan as 'Kotla Feroz Shah' and now known by locals as 'Feroz Shah Kotla'. It contains ruins of both the northern and southern parts of the citadel enclosure that is currently seen with numerous modern buildings. You will also notice the ruins of an imposing entrance and exit gateway that overlooked the western side of the enclosure and flanked by Bastions on either side. The grandeur and beauty of this Palace also fascinated Sultan Timur of the 14th Century AD and is sometimes compared with Windsor Palace of England. After the defeat of the Tughluq dynasty, this Palace was abandoned in 1490 AD.MamlukStructurally from the outside, the Mosque is very impressive, holding its own with its impressive cornice and the protruding verticals of its facade, even though it stands in the shadows of the massiveCitadel. As one enters the Mosque from Sharia el Qalaa, there is an impression of height, especially from the towering doors decorated in a Mameluke fashion. Even during the Mameluke error inCairo, building space was at a premium. Thus the outer walls are somewhat askew, in order to fit the available lot, but these designers had a wonderful way of creating the impression of uniform cubistic effect inside regardless.