What cultural monument was created in the Ancient Mesopotamia?

We are talking about the territory of modern Iraq and Syria. This territory was called Mesopotamia or Mesopotamia or Mesopotamia because of the Tigris and Euphrates rivers. The following cultural monuments were created there:

Hanging Gardens of Babylon. They were built during the years of the New Babylonian kingdom under Nebuchadnezzar II. Until now, the authenticity of their existence is questionable. They were created in the 7th century BC.
Ziggurat. One of the oldest buildings in the region, dates back to the 21st century BC. 500 years younger than the Cheops pyramid.
Ishtar gate. Also built by Nebuchadnezzar II in 575 BC.
The first library in the history of the world in Nineveh. It was created by the king of Assyria Ashurbanapal, and cuneiform tablets and papyri were kept in it.