Sultanahmet mosque (The Blue Mos­que): Built by the architect Mimar' Sedefkar Mehmet Aða for Ahmet I, between 1609-1616. Its six minarets are uni­que. Surrounded on three sides by courtyards with five portals, the portico is covered by 30 tupolas supported by 26 marble columns with stalactite capitals. In the centre of the main courtyard is a hexagonal fountain. The mosque itself has three doors. The largest opens into the main courtyard, and it is this door which is use d as the entrance today. The 'mosque is almost square in plan. The central dome is supported by four. mar­ble piers with four arches sprung between. The dome is flanked on all four sides by a semi-dome with cupolas at the, corners. The extraordinary height of the dome (23 ms.) allowed for an unusual number of windows (260 in all) which provide the interior with a warm, overall, lig ht which illuminates the rich tiling and tracery. According to ttte sources, thete are a total of 21,043 faience tiles, eaCh valued at 18 silver akches. ~

The sultan's gallery - mahfil- is in the left corner .of the mosque, and has a fine mihrab decorated with mosaic and green tiles. The mother-of-pearl inlay door, gilded faience and filigree relief-carved mar­ble balustrades are extraordinarily fine. The mosque, also known as the Blue Mosque, is so-called af ter the faience revetments. Those on the gallery level are particularly fine. The blue-green faience wallpanels are countered by tracery on the dome in similar tones. The dome is also inscribed with the names of the caliphs. it was from the steps of the mar­ble pulpit - mimber - that Mahmut II declared the dissolution of the Janissary in 1826. The mihrab, also in white n'lar­ble is decorated with precious stones and a piece of rock from the Ka'ba.

The mausoleum of Ahmet I, founder of the mosque, is situated to the northeast together with those of Osman II and Murat ýv. Until the 19 century Sultanahmet mosque was the traditional starting point for the pilgrimage to Mecca.