A part of the wall in the old citadel (Bhadra) of the mosque built by Ahmed Shah's slave, Sidi Sayyid, is celebrated all over the world for its exquisite stone window tracery - a superb example of delicate carving that transforms stone into filigree. Sidi Sayyid's Mosque is famed for the ten magnificent 'jali' screens lining its upper walls and sits in the centre of a busy traffic circle in the northwest corner of Bhadra. The two semicircular screens high on the western wall are the most spectacular with floral designs exquisitely carved out of the yellow stone so common in Ahmedabad's mosques. The eastern face is open, revealing a host of pillars that divide the hall into heroes and animals from popular Hindu myths - one effect of Hindu and Jain craftsmanship on an Islamic tradition that rarely allowed the depiction of living beings in its mosques. The gardens around it afford good views of the screens. Women cannot enter this mosque The solid fortified citadel, Bhadra, built of deep red stone in 1411 AD as Ahmedabad's first Muslim structure, is relatively plain in comparison to later mosques. The palace inside is now occupied by offices and off-limits to tourists, but you can climb to its roof via a winding staircase just inside the main gateway and survey the streets below from behind its weathered bastions.