The arch was used profusely in the architecture of the citadel. The arch in traditional construction was nearly always employed as a structural element and not as a decorative one. Of course, there was always the choice of which type to use and where to apply- a question which may have entailed some aesthetic consideration too.
The different types of arches found at the citadel are as follows:
1. Round Arch: is a semi-circular arch which was employed commonly for arcades, windows, and niches. For arcades, the arches were always constructed in stone and rested on stone columns, while for other places they were constructed in brick. This was because it was not easily possible to construct slender and strong columns in brick that could bear the huge load of the arcade and the rood above.
2. Pointed Arch: is the typical arch used in Islamic architecture. It was employed in the demolished South Gate of the citadel and in many places such as arcades, iwans, doors, windows, and niches.