Main gate of the Aleppo citadel. Photo: TMK, October 2008.
Here’s a good little free guide to the Aleppo citadel, courtesy of the Aga Khan Trust (via AWOL). It has excellent illustrations to help visitors make sense of the multi-period monuments on the citadel. The Aga Khan Trust has similar guides to the Castle of Salah ah-Din and Masyaf Citadel where they also have been responsible for conservation works and site management.