Stonecutting and Early Stereotomy in the Fatimid Walls of Cairo

Abstract

Bab el Nasr gate, which was built between 1087 and 1092, is one of the three remaining gates in the Cairo Fatimid walls. Inside the walls, there are a great variety of stonework pieces that reveal the stereotomic knowledge of their executors. Specially, the inner space of Bab el Nasr gate is covered by a groin vault which stands out for the accuracy of its construction, despite its early execution date. In order to analyse the geometry and design of its construction, a photogrammetric survey has been carried out with the aim of comparing the solution executed in Bab el Nasr with other contemporary vaults. Furthermore, this paper reviews the Renaissance stonecutting texts and manuscripts which, centuries later, include the proposed solution in Cairo, and which are the basis for the creation of Descriptive Geometry as a discipline.