The Serapeum, also known as the Temple of Serapis, was erected for the new cult in Alexandria, as the Greeks came to settle in Alexandria together with the Egyptians. A serapeum is a temple or other religious institution dedicated to the syncretic Hellenistic-Egyptian god Serapis, who combined aspects of Osiris and Apis in a humanized form that was accepted by the Ptolemaic Greeks of Alexandria.
The Serapeum was built during the reign of Ptolemy III Euergetes (246–221 BCE), on a hill to the west of the city just outside the ancient Ptolemaic city boundary. A stair case leads to the Serapeum, on the left hand side is a huge scarab made of red granite bearing some hieroglyphic inscriptions. According to ancient accounts the Serapeum was the most magnificent temple of Alexandria and the temple complex also included shrines to Harpocrates and Isis, who with Serapis, formed the Alexandrian Trinity.