Some later Bahminid royal tombs are double, with two units of the usual rectangle-with-dome form combined, one for the ruler and the other for his family, as at the Haft Dombad ("Seven Domes") group of royal tombs outside Gulbarga. The Mahmud Gawan Madrasa (begun 1460s) is a large ruined madrasa "of wholly Iranian design" in Bidar founded by a chief minister, with parts decorated in glazed tiles imported by sea from Iran. Outside the city the Ashtur tombs are a group of eight large domed royal tombs. These have domes which are slightly pulled in at the base, predating the onion domes of Mughal architecture.