Merv (Turkmen: Merw, from Persian: مرو, Marv, sometimes transliterated Marw or Mary; cf. Chinese: 木鹿, Mulu), formerly Achaemenid Satrapy of Margiana, and later Alexandria and Antiochia in Margiana (Greek: Αντιόχεια της Μαργιανής), was a major oasis-city in Central Asia, on the historical Silk Road, located near today's Mary in Turkmenistan. Several cities have existed on this site, which is significant for the interchange of culture and politics at a site of major strategic value. It is claimed that Merv was briefly the largest city in the world in the 12th century. The site of ancient Merv has been listed by UNESCO as a World Heritage Site.