Which of the seven wonders was built first?

The Great Pyramid of Giza is the oldest of the Seven Wonders of the Ancient World, completed around 2560 BCE. It was constructed as a tomb for the Egyptian Pharaoh Khufu and remains the only wonder still largely intact today. The other wonders were built much later, with the earliest among them, the Hanging Gardens of Babylon, believed to have been constructed around the 6th century BCE.