The pointed arch, one of the defining attributes of Gothic, was earlier featured in Islamic architecture, Though it did not have the same functions. Precursor of pointed arch appeared in Byzantine and Sassanian architectures, This was evidenced in early church building in Syria and occasional secular structures, like the Karamagara Bridge; in Sassanian architecture, employed in palace and sacred construction. These pre-Islamic arches were decorative rather than structural in their function. The pointed arch as an architectonic principle was first clearly established in Islamic architecture; as an architectonic principle, the pointed arch was entirely alien to the pre-Islamic world. Use of the pointed arch seems to have taken off dramatically in Islamic architecture. It begins to appear throughout the Islamic world in close succession after its adoption in the late Umayyad or early Abbasid period. Some examples are the Al-Ukhaidir Palace (775 AD), the Abbasid reconstruction of the Al-Aqsa mosque in 780 AD, the Ramlah Cisterns (789 AD), the Great Mosque of Samarra (851 AD), and the Mosque of Ibn Tulun (879 AD) in Cairo. It also appears in one of the early reconstructions of the Great Mosque of Kairouan in Tunisia, and the Mosque–Cathedral of Córdoba in 987 AD. The pointed arch had already been used in Syria, but in the mosque of Ibn Tulun we have one of the earliest examples of its use on an extensive scale, some centuries before it was exploited in the West by the Gothic architects.