The Tomb of Abbasid Caliphs lies next to the Mosque of Sayyida Nafisa in El Khalifa Street. It was erected by the Abbasid caliph’s Ambassador in Egypt Abu Nadia in 1242. The Mamluk sultan Baybars El-Bunduqdari, who reestablished the Abbassid Caliphate in Egypt in 1261, ordered to construct this mausoleum to bury his two sons. The shrine is preceded by a large courtyard with a vaulted hall. From outside, the tomb has many cusped and ribbed keel arches that characterize most of the buildings of that period. Inside the mausoleum appear the cenotaphs of the sons of Baybars and children of Abbasid Caliphs and Abu Nadia. The Mihrab of the tomb is designed on the Fatimid style using a niche that dominates the sanctuary of the tomb, but it is distinguished by its fine lace- like carving.