For thousands of years, southern Mesopotamia (ancient Iraq) was home to hunters, fishers, and farmers, exploiting fertile soil, rivers, and abundant animals. By around 3200 B.C., the largest settlement in southern Mesopotamia, if not the world, was Uruk: a true city dominated by monumental mud-brick buildings decorated with mosaics of painted clay cones embedded in the walls, and extraordinary works of art. Large-scale sculpture in the round and relief carving appeared for the first time, together with metal casting using the lost-wax process. Simple pictographs were drawn on clay tablets to record the management of goods and the allocation of workers’ rations. These pictographs are the precursors of later cuneiform writing. Until around 3000 B.C., objects inspired by Mesopotamia were found from central Iran to the Egyptian Nile Delta. However, this widespread culture collapsed and Mesopotamia looked inward for the next few centuries. Yet cities such as Uruk continued to expand. During the following Early Dynastic period (2900–2350 B.C.), when city-states dominated Mesopotamia, the city rulers gradually grew in importance and increasingly sought luxury materials to express their power. These goods, often from abroad, were acquired either by trade or conquest. At this time Uruk was surrounded by a massive wall, which according to tradition was built on the orders of King Gilgamesh. Although he may have been an actual king of Uruk around 2700 B.C., Gilgamesh became the hero of many later stories and epics.
metmuseum.org
The greatest city of the Assyrian Empire was Nineveh. It became the largest city in the world at the height of the Assyrian Empire. The city was largely built under the rule of King Sennacherib around 700 BC. The great walls of Nineveh enclosed an area of 7 square kilometres and had 15 gates. There were 18 canals that brought water to different areas of the city.
Nineveh was home to King Ashurbanipal, the last great king of the Assyrian Empire. Under his rule a great library was built that housed over 20,000 clay tablets. Much of what we know about Mesopotamia comes from these tablets.
ducksters.com
The city of Akkad was the center of the world's first empire, the Akkadian Empire. The people of Akkad, under the leadership of Sargon the Great, conquered many of the Sumerian city-states and took control of Mesopotamia. The Akkadian language took the place of Sumerian and continued to be the primary language of the region into the Babylonian and Assyrian Empires. Archeologists still haven't found the city of Akkad and are unsure where it is located. It was likely located in southern Mesopotamia just east of the Tigris River.
:
The ancient city of Ashur is located on the Tigris River in northern Mesopotamia in a specific geo-ecological zone, at the borderline between rain-fed and irrigation agriculture. The city dates back to the 3rd millennium BC. From the 14th to the 9th centuries BC it was the first capital of the Assyrian Empire, a city-state and trading platform of international importance. It also served as the religious capital of the Assyrians, associated with the god Ashur. The city was destroyed by the Babylonians, but revived during the Parthian period in the 1st and 2nd centuries AD.
Founded in the 3rd millennium BCE, the most important role of Ashur was from the 14th to 9th century BCE when it was the first capital of the Assyrian empire. Ashur was also the religious capital of Assyrians, and the place for crowning and burial of its kings. Criterion iv: The excavated remains of the public and residential buildings of Ashur provide an outstanding record of the evolution of building practice from the Sumerian and Akkadian period through the Assyrian empire, as well as including the short revival during the Parthian period.
unesco.org
Persepolis was the capital of the Persian Empire. The name is Greek for 'Persian city'. The city was originally built by Cyrus the Great around 515 BC. Other kings such as Darius I and Xerxes completed the palace and other buildings. The city was located in southeast Iran.
Much of the city is currently being reconstructed by archaeologists. Some of the structures include the Gate of Nations, the Throne Hall and the Apadana Palace.
ducksters.com
Babylon was the capital city and center of the Babylonian Empire. During its peak, Babylon was the largest city in the world with populations exceeding 200,000 people. It was home to kings such as Hammurabi and Nebuchadnezzar as well as the fabled Hanging Gardens of Babylon which are one of the Seven Wonders of the Ancient World. Babylon is located in central Mesopotamia along the banks of the Euphrates River. Today the ruins of the city can be found around 50 miles south of Baghdad, Iraq.
https://www.ducksters.com/history/mesopotamia
Nimrud became the capital city of the Assyrian Empire in the 13th Century BC. Although the city later fell into ruins, the great King Ashurnasirpal II rebuilt the city and made it the Assyrian capital once again in 880 BC. Nimrud was home to some of the most magnificent palaces built in ancient history. The palace of Shalmaneser III covered over 12 acres and had more than 200 rooms.
https://www.ducksters.com/history/mesopotamia