Perhaps the most characteristic arch type of Moroccan and western Islamic architecture generally is the so-called "Moorish" or "horseshoe" arch. This is an arch where the curves of the arch continue downward past the horizontal middle axis of the circle and begin to curve towards each other, rather than just being semi-circular (forming half a circle only). This arch profile became nearly ubiquitous in the region from the very beginning of the Islamic period. The origin of this arch appear to date back to the preceding Byzantine period across the Mediterranean, as versions of it appear in Byzantine-era buildings in Cappadocia, Armenia, and Syria. They also appear frequently in Visigothic churches in the Iberian peninsula (5th-7th centuries). Perhaps due to this Visigothic influence, horseshoe arches were particularly predominant afterwards in al-Andalus under the Umayyads of Cordoba, although the Andalusi arch was of slightly different profile than the Visigothic arch. Arches were not only used for supporting the weight of the structure above them. Blind arches and arched niches were also used as decorative elements. The "mihrab" (niche symbolizing the "qibla") of a mosque was almost invariably in the shape of horseshoe arch. Starting in the Almoravid period, the first pointed or "broken" horseshoe arches began to appear in the region and became more widespread during the Almohad period. This arch is likely of North African origin, since pointed arches were already present in earlier Fatimid architecture further east.