Ai-Khanoum (/aɪ ˈhɑːnjuːm/, meaning 'Lady Moon'; Uzbek: Oyxonim) is the archaeological site of a Hellenistic city in Takhar Province, Afghanistan. The city, whose original name is unknown, was likely founded by an early ruler of the Seleucid Empire and served as a military and economic centre for the rulers of the Greco-Bactrian Kingdom until its destruction c. 145 BC. Rediscovered in 1961, the ruins of the city were excavated by a French team of archaeologists until the outbreak of conflict in Afghanistan in the late 1970s.
The city was probably founded between 300 and 285 BC by an official acting on the orders of Seleucus I Nicator or his son Antiochus I Soter, the first two rulers of the Seleucid dynasty. There is a possibility that the site was known to the earlier Achaemenid Empire, who established a small fort nearby. Ai-Khanoum was originally thought to have been a foundation of Alexander the Great, perhaps as Alexandria Oxiana, but this theory is now considered unlikely. Located at the confluence of the Amu Darya (a.k.a. Oxus) and Kokcha rivers, surrounded by well-irrigated farmland, the city itself was divided between a lower town and a 60-metre-high (200 ft) acropolis. Although not situated on a major trade route, Ai-Khanoum controlled access to both mining in the Hindu Kush and strategically important choke points. Extensive fortifications, which were continually maintained and improved, surrounded the city.