These cylinders were buried in the corners of large buildings as foundation tablets. They were intended to be discovered and read by future kings whenever repairs were made to the building.
These were discovered in the ruins of the city of Babylon. They describe King Nebuchadnezzar's building projects, including the restoration of temples and repairs to his father's palace after flooding. He did not think this palace was grand enough for himself, so he built himself a new palace on the northern side of Babylon. It had a blue parapet and massive fortification walls. He also built new city walls around the east of the city, and built himself a third palace next to the River Euphrates. This was known as the Summer Palace. It had special ventilation shafts to keep the rooms cool in the summer heat. These palaces were built with baked bricks fixed together with bitumen. The roofs and doors were made of expensive imported timber.
Nebuchadnezzar says: "Is this not magnificent Babylon, which I have built as a royal capital by my mighty power and for my glorious majesty." (Dan 4:30). After boasting in this way, he was condemned to live away from human society, and eat grass like an ox for seven years.