Iran has a rich archaeological and architectural heritage and first came centre stage in the 6th century BC under the Achaemenid dynasty. Named after Achaemenes, the 7th-century BC ruler of Anshan, the dynasty was effectively founded by Cyrus the Great, creator of the Persian Empire. At its zenith, the Empire stretched from the River Indus in the East to Thrace and Libya in the West and from the Persian Gulf to the Caucasus in the North, bringing excellent administration, law, reliable currency and postage systems and religious tolerance. Against this background, art and architecture flourished as is evidenced in the legacy from these distant times. This itinerary also does justice to the Sasanian Empire and to the splendid buildings of the Islamic period with the fall of Iran to the Arabs in 642 AD and the advent of the Muslim religion and a near millennium of conquests by foreign powers. The magnificent tower tombs, mosques, madrasas and shrines of Iran are an enduring testament to these conquerors.