Hagia Sophia, which is used as museum at the present, was constructed in such a short period of five years between 532-537 and during the period of Eastern Roman Emperor I. Iustinianos (527-565). Architects of Hagia Sophia Church are Anthemious from Tralles (Aydın9 and Isidoros from Miletus (Balat-Söke). Church has a basilical plan. It is composed of galleries, with abscissa, three naves, two narthexes as inside and outside one, which surround the structure inwardly from three directions and are stepped up through ramps from four corners of the structure. Structure is in the internal sizes of 100x70m. Dome is in the average diameter of 31,5 m. and its height from the ground is 55m. There are 40 windows in tambour of the dome. 40 columns are used in the ground floor of the structure and 67 columns are used in the galleries and total used columns are 107 pieces. Internal walls of the structure are covered with marmoreal sheets with various colors. Again top secrions of internal walls and dome and vault cover are coated with mosaics. Some of mosaics are fallen out. All of mosaics with figures belong to the period after 9th Century. There are Vestibule Mosaic, depicting The Virgin Mary, Jesus The Child, Emperor Constantine I. (306-337) and Iustinianos I, in the south gate of the structure; Imperial Mosaic, depict in Emperor VI. Leon (886-912), The Virgin Mary and The Archangel Gabriel, on the niddle door, opened from Internal narthex to main location and called “Emperor Gate”; Mosaic of The Virgin Mary and Jesus The Child in her lap in the abscissa and The Archangel Gabriel in Bema vault in the right; Deisis mosaic, depicting The Virgin Mary, Jesus and John the Baptist in the south gallery wall; mosaic images of Emperor Constantine Monomakhos (1042-1055) and Empress Zoe in the left and Emperor Ioannes Kommenos, Empress Eirene and their child Alexios in the right in east wall of south gallery. There are mosaic of Emperor Alexandros in the internal wall of north gallery; mosaic descriptios of saint named Ionnes Khyrisostomos, Young Ignatios and Ignatios Theophoros in niches in the internal front of north wall of structure. Hagia Sophia is converted into mosque after conquest of Istanbul 1453. A great restoration is conducted between 1847-1849 during the reign of Sultan Abdülmecit (1839-1861). Structure is converted intro museum in November 24, 1934 and it is opened for public visits as museum in 1935. Four minarets are added from outside to structure and niche, pulpit, muezzin and Sultan messes, preach desk are added into it in the Ottoman period; tables, containing names of Allah, Mohammed, first four caliphs (Abu Bakr, Umar, Utmman, Ali) and grandsons of Mohammad, names as Hassan and Husein, are hung in its internal walls. The Light Surah is written onto the main dome. Library structure is added among buttress in south direction of the structure. There are structures of Baptism place, Muvakkithane (time adjusting house), Ottoman Elemantry-Primary School, Water Tank with a fountain, School remains, Almshouse and Chamber of Treasurty abd also burial place, containing Sultan II. Selim (1566-1574), III. Murat (1574-1595), III Mehmet (1595–1603) and Tomb of Sultan’s Sons, Sultan I. Mustafa (1617-1623) and Sultan Ibrahim (1640-1648) in the garden of museum. Sultan Pavilion, which is used as small mosque at the present, is located in Topkapi Palace direction of Hagia Sophia.