What city did the flood hero Utnapishtim live in before the deluge?

Before the deluge, Utnapishtim lived in the city of Shuruppak.

In the flood narrative of the Epic of Gilgamesh, Utnapishtim is introduced as a man of Shuruppak and the son of Ubara-Tutu. Shuruppak was an important ancient Mesopotamian settlement on the Euphrates in southern Iraq, known in Sumerian tradition as a center of learning and scribal culture.

The god Ea secretly warns Utnapishtim that the gods intend to send a flood. He tells him to abandon his house, build a boat, and preserve living creatures. Utnapishtim follows the instructions, survives the catastrophe, and is later granted immortality with his wife. Gilgamesh eventually travels to him seeking the secret of escaping death.

Shuruppak is also significant outside the myth. Archaeologists found evidence of an ancient flood layer there, often dated broadly to the early third millennium BCE, though it cannot be proved to be the historical event behind the poem. Babylon, Nippur, and Uruk are major Mesopotamian cities, but none is Utnapishtim’s home in the Gilgamesh account.