Ur (//; Sumerian: Urim; Sumerian Cuneiform: 𒌶𒆠 URI5KI, 𒋀𒀕𒆠 URIM2KI or 𒋀𒀊𒆠 URIM5KI; Akkadian: Uru; Arabic: أور; Hebrew: אור) was an important Sumerian city-state in ancient Mesopotamia, located at the site of modern Tell el-Muqayyar (Arabic: تل المقير) in south Iraq's Dhi Qar Governorate. Although Ur was once a coastal city near the mouth of the Euphrates on the Persian Gulf, the coastline has shifted and the city is now well inland, on the south bank of the Euphrates, 16 kilometres (9.9 miles) from Nasiriyah in modern-day Iraq.
The city dates from the Ubaid period circa 3800 BC, and is recorded in written history as a city-state from the 26th century BC, its first recorded king being Mesannepada. The city's patron deity was Nanna (in Akkadian, Sin), the Sumerian and Akkadian (Assyrian-Babylonian) moon god, and the name of the city is in origin derived from the god's name. UNUGKI, literally "the abode (UNUG) of Nanna".
The site is marked by the partially restored ruins of the Ziggurat of Ur, which contained the shrine of Nanna, excavated in the 1930s. The temple was built in the 21st century BC (short chronology), during the reign of Ur-Nammu and was reconstructed in the 6th century BC by Nabonidus, the last king of Babylon. The ruins cover an area of 1,200 metres (3,900 ft) northwest to southeast by 800 metres (2,600 ft) northeast to southwest and rise up to about 20 metres (66 ft) above the present plain level.