During the era of the Umayyad Caliphate (661 AD – 750 AD), regarding the Byzantine impact on ancient Islamic architecture, the Byzantine artistic heritage was a source fundamental for the new Islamic art, especially in Syria and Palestine. There are notable Byzantine influences that can be detected in characteristic early Islamic monuments in Syria and Palestine, such as on the 691 AD Dome of the Rock in Jerusalem, or the Umayyad Mosque in Damascus. While the Dome of the Rock makes clear references in its plan - and partly in its decoration - to Byzantine art, the plan of the Umayyad Mosque also has a notable resemblance to the Christian basilicas of the 6th and 7th centuries, but was modified and expanded on the transversal axis and not on the normal longitudinal axis as in Christian basilicas. This modification better serves the liturgy for Islamic prayer. The original mihrab of the mosque is located almost in the center of the eastern part of the Qibla wall and not in the center, a feature that can be explained by the fact that the architect may have tried to avoid the impression of a Christian apse that would result from the placement of the mihrab in the center of the transept. The tiles, geometric patterns, multiple arches, domes, and polychrome bricks and stones that characterize Islamic and Moorish architecture were to some extent influenced by Byzantine architecture.