Mosque architecture in Morocco was heavily influenced from the beginning by major well-known mosques in Tunisia and al-Andalus (Muslim Spain and Portugal), two countries from which many Arab and Muslim immigrants to Morocco originated. The Great Mosque of Kairouan and the Great Mosque of Cordoba, in particular, were models of mosque architecture. Accordingly, most mosques in Morocco have roughly rectangular floor plans and follow the hypostyle format: they consist of a large prayer hall upheld and divided by rows of horseshoe arches running either parallel or perpendicular to the qibla wall (the wall towards which prayers faced). The qibla (direction of prayer) was always symbolized by a decorative niche or alcove in the qibla wall, known as a "mihrab". Next to the mihrab there was usually a symbolic pulpit known as a "minbar". The mosque also normally included, close to entrance, a "sahn" (courtyard) which often had fountains or water basins to assist with ablutions. In early periods this courtyard was relatively minor in proportion to the rest of the mosque, but in later periods it became a progressively larger until it was equal in size to the prayer hall and sometimes larger. Lastly, mosque buildings were distinguished by their minarets: towers from which the muezzin issues the call to prayer to the surrounding city. (This was historically done by the muezzin climbing to the top and projecting his voice over the rooftops, but nowadays the call is issued over modern megaphones installed on the tower.) Moroccan minarets traditionally have a square shaft and are arranged in two tiers: the main shaft, which makes up most of its height, and a much smaller secondary tower above this which is in turn topped by a finial of copper or brass spheres. Some Moroccan minarets have octagonal shafts, though this is more characteristic of the northern parts of the country. Inside the main shaft a staircase, and in other cases a ramp, ascends to the top of the minaret.