A. Isin (modern Ishan Bakhriyyat) Isin rose to prominence in the early second millennium B.C. when it took control of territories once ruled by Ur. For the past 30 years a German archaeological team has excavated the site, uncovering a late-second-millennium B.C. temple to Gula, a goddess associated with healing.

B. Kalhu (modern Nimrud) Called “Calah” in the Bible, Kalhu was the capital of the Assyrian king Ashurnasirpal II (883–859 B.C.). The site was first excavated in 1845 by British explorer Austen Henry Layard, who mistakenly thought he had uncovered the remains of ancient Nineveh.

C. Kisiga (modern Tell el-Lahm) Kisiga was ancient Sumer’s principal seaport. The city was dependent on overseas trade and was the traditional birthplace of the god Marduk, son of the water god Enki.

D. Mashkan-shapir (modern Tell Abu Duwari) A city of canals, Mashkan-shapir was occupied from the early third millennium B.C. until 1720 B.C. Its buildings—including a ziggurat serving as a primary sanctuary to Nergal, god of death—were aligned along waterways and were surrounded by walls.

E. Nippur (modern Nuffar) In Nippur, the most important Sumerian religious center, the sky god Enlil was worshiped. The third-millennium B.C. ruins of the Temple of Enlil, the Temple of Inanna (goddess of love and war) and a ziggurat built by king Ur-Nammu can today be seen at the site. At Nippur archaeologists have also found thousands of cuneiform tablets, dating from the late third millennium B.C. to the late first millennium B.C.