The Alai Darwaza is the only entrance remaining of four added to the Qutb Complex by Ala al-Din Khalji (reg. 1296 - 1316). Located on the southeastern edge of the complex, its elaborate treatment suggests that it may have been used as a gate to the city itself through the extension of the Qutb mosque.

In contrast to the existing Qutb Mosque, which was built with the spolia of the existing temples on the site, the Alai Darwaza was a new structure. The gate is square in plan: its exterior length is 17.22 meters, its walls are 3.3 meters thick, and its interior length is 10.6 meters. From its floor to its domed ceiling, its height is 14.3 meters. Its wide, shallow dome rests on an octagonal base, and the transition from the octagonal base to a circular dome is achieved with squinches (muqarnas). On the exterior, the dome is plastered.

The gate stands on a plinth clad with red sandstone with carved friezes. On the south (main) elevation of the gate, steps beginning at the plinth lead into the gate itself. Its exterior is clad with intricately carved red sandstone and white marble bands carved with calligraphic inscriptions in Naksh script or geometric patterns. In the center springs the gate itself, a true arch (as opposed to the older, local trabeated construction visible in other parts of the Qutb complex), ornamented with slender pillars. The gate is bilaterally symmetrical on its south elevation: flanking the gateway on either side are two small arched windows with delicate latticework (jalis) just above the plinth level. Above these lower-level windows are shallow rectangular niches (again, two on either side of the gate) created with concentric bands of red sandstone and white marble carvings.

On the eastern and western sides, the arrangement of central archway flanked by a jaliwork window on the lower level and rectangular niches on the upper level is repeated. However, on the western elevation, this sandstone and marble niche revetment has fallen off. Where the volume of the gate joins the complex wall, the blind window on the northwestern corner has been half-covered by the complex wall.

The gate of the north elevation, facing into the complex, is a semicircular arch. The south, east, and west elevations each feature horseshoe arches with spearheaded decorations in the intrados and a decorative parapet above.

In addition to its pleasing symmetry, the Alai Gate is notable for its finely carved surfaces. On the south elevation, patterns range from arabesques to more Hindu motifs such as rounded lotus buds and leafy tendrils.

Sources:

Asher, Catherine B. Architecture of Mughal India. Cambridge; New York: Cambridge University Press, 1992. 6,7.

Balasubramaniam, R. The World Heritage Complex of the Qutub. New Delhi: Aryan Books International, 2005. 100-103.

Nabi Khan, Ahmad. Islamic Architecture in South Asia: Pakistan - India - Bangladesh. Oxford, New York: Oxford University Press, 2003. 33-35.

Sahai, Surendra. Indian Architecture: Islamic Period, 1192 - 1857. New Delhi: Prakash Books India, 2004. 19-21.

Volwahsen, Andreas and Henri Stierlin, editors. Islamic India in Volume 8 of Architecture of the World. Cologne, Germany: Taschen Verlag, 1994. 13-17.