The name Serapeum is most often used to refer to the burial place of the sacred Apis bulls at Saqqara. It consisted of a huge underground complex to the north-west of the Step Pyramid of Djoser where the bulls were buried in enormous granite sarcophagi between the 18th Dynasty and Ptolemaic times. Not far away was also the tomb of one of the sons of Ramesses II, Prince Khaemwaset, who had part of the Serapeum constructed. A long causeway flanked by numerous sphinxes led the way to the Serapeum from the valley edge. The name Serapeum is also used to refer to any temple of the god Sarapis, especially that in Alexandria which was built by Ptolemy III and razed to the ground in 391 AD on the orders of the Emperor Theodosius. The temple complex, which also housed parts of the library of Alexandria, was famous for the cult statue of Sarapis made by Bryaxis.