Ancient Egypt was a civilization which began more than three thousand years ago in the Nile Valley. A three-major periods epoch (Old Kingdom, Middle Kingdom, New Kingdom) was introduced for convenience which consists of 31 dynasties. Nowadays, Egypt is a famous tourist attraction. One can see the Pyramid of Cheops, the Pyramid of Chephren and the Pyramid of Menkaure, the Mortuary Temple of Queen Hatshepsut, the Abu Simbel temples, the Luxor and Karnak temples as well as many other buildings, statues and art. It became an empire during the rule of Tuthmosis III, who ruled over a large area from Nubia to the Euphrates River in Asia. Ancient Egyptians believed in lot of gods, but Pharaoh Akhenaten introduced a new religion with only one god – Aton. The religion disappeared when his successor took over. The greatest discovery was the Tutankhamen's tomb. It was conducted by Howard Carter in 1922. During the Old Kingdom, there were frequent invasions by various peoples and rulers would often change. As a result, Egypt was slowly but surely disappearing. After the arrival of Alexander the Great in 332 BC, the Ptolemaic dynasty got to power. They were the last dynasty of Ancient Egypt.