Walls and Gates, Baghdad
When Abu Ja'far Al-Mansour built Baghdad in 762 AD, it was a round city, with walls and four gates at an angle of 90 degrees for defensive purposes. Main administrative and religious buildings were placed near the center for easy approach. Although the capital was abandoned for Samarra in AD 836, the Abbasids went back to it in AD 892, and the city continued to expand on both sides of the river. Al-Mustarshid Billah (1118 - 1135 AD), was the first Caliph to build a wall on the eastern (Rusafa) side of the city, which remained until late in the 19th century.
The Eastern Wall was very thick, built from bricks, with several watchtowers and a deep moat connected with the Tigris. The main gates were: Mu'adham (North) Gate, Dhafariya (Wastani) Gate, Halaba (Talisman) Gate, and Basaliya Gate.
The only gate extant today is the Wastani Gate, near the Mausoleum of Omar Al-Sahrawardi - just off Sheikh Omar Street. It is a high cylinder-shaped tower with a ground circumference of 56 meters, 14.5 meters high, crowned with an octagonal dome. On the northwest side it has a portal 3 meters wide with a pointed arch, in front of which is a bridge across the moat. On the southwest side of the tower is a door that leads to an even bigger and higher bridge over the moat.
In the course of the extensive construction works undertaken by the government, workers on the speedy way near South Gate hit upon the remnants of what transpired to have been Halaba (Talisman) Gate, which was destroyed by the Ottomans in 1917. It had been last renewed some 7 centuries earlier in 1221, it has now been preserved with care, to stand as another monument telling a part of the history of Baghdad.