by the mughals until 1687, greatly developed the city and its surrounding region, building many mosques such as the Mecca Masjid, Khairtabad Mosque, Hayat Bakshi Mosque and Toli Mosque, as well as the Golconda Fort, tombs of the Qutb Shahis, Charminar, Char Kaman and Taramati Baradari. Bengal Sultanate The Bengal Sultanate (1352–1576) normally used brick as the primary construction material of large buildings, as pre-Islamic buildings had done. Stone had to be imported to most of Bengal, whereas clay for bricks is plentiful. But stone was used for columns and prominent details, usually re-used from Hindu or Buddhist temples. The early 15th century Eklakhi Mausoleum at Pandua, Malda or Adina, is often taken to be the earliest surviving square single-domed Islamic building in Bengal, the standard form of smaller mosques and mausoleums. But there is a small mosque at Molla Simla, Hooghly district, that is possibly from 1375, earlier than the mausoleum. The Eklakhi Mausoleum is large and has several features that were to become common in the Bengal style, including a slightly curved cornice, large round decorative buttresses at the corners, and decoration in carved terracotta brick. These features are also seen in the Choto Sona Mosque (around 1500), which is in stone, unusually for Bengal, but shares the style and mixes domes and a curving "paddy" roof based on village house roofs made of vegetable thatch. Such roofs feature even more strongly in later Bengal Hindu temple architecture, with types such as the do-chala, jor-bangla, and char-chala. For larger mosques, Bengali architects multiplied the numbers of domes, with a nine-domed formula (three rows of three) being one option, surviving in four examples, all 15th or 16th century and now in Bangladesh, although there were others with larger numbers of domes. Buildings in the style are the Nine Dome Mosque and the Sixty Dome Mosque (completed 1459) and several other buildings in the Mosque City of Bagerhat, an abandoned city in Bangladesh now featured as a UNESCO World Heritage Site. These show other distinctive features, such as a multiplicity of doors and mihrabs; the Sixty Dome Mosque has 26 doors (11 at the front, 7 on each side, and one in the rear). These increased the light and ventilation. Further mosques include the Baro Shona Masjid; the Pathrail Mosque, the Bagha Mosque, the Darasbari Mosque, and the Kusumba Mosque. Single-domed mosques include the Singar Mosque, and the Shankarpasha Shahi