The ancient Sumerian city-state known as Ur was located in which modern-day country?

Ur was a city-state of Sumer, southern Mesopotamia, in what is now modern-day Iraq. It was located at the site of modern Tell el-Muqayyer in south Iraq's Dhi Qar Governate. The site is marked by the partially restored ruins of the Ziggurat of Ur, which was excavated in the 1930s.

Ur was a significant port city on the Persian Gulf which began, most likely, as a small village in the Ubaid Period of Mesopotamian history (5000-4100 BCE). It was an established city by 3800 BCE and continually inhabited until 450 BCE. Ur's associations with the Christian Bible have made it famous in the modern-day but it was a significant urban center long before the biblical narratives were written.

In its time, Ur was an important trade center owing to its location at a pivotal point where the Tigris and Euphrates rivers run into the Persian Gulf. Archaeological excavations have substantiated that, early on, Ur possessed great wealth and the citizens enjoyed a level of comfort unknown in other settlements of the region.

After a long period of time, due to climate change and the overuse of the land, more people migrated to the northern regions of present-day Iraq or south toward the ancient land of Canaan. Ur slowly dwindled in importance as the Persian Gulf receded further and further south from the city and eventually fell into ruin around 450 BCE.