Wikipedia
A serapeum is a temple or other religious institution dedicated to the syncretic Hellenistic- Ancient Egyptian deity Serapis, who combined aspects of Osiris and Apis in a humanized form that was accepted by the Ptolemaic Greeks of Alexandria. There were several such religious centers, each of which was a serapeion or, in its Latinized form, a serapeum.
Usage examples of "serapeum".
The main attack will come between Toussoum and Serapeum, at half past three.
A great temple, the Serapeum, was set up by Ptolemy I at which a sort of trinity of gods was worshipped.
This it was that filled the Serapeum with weeping penitents and brought the converts into the gloom and gore of the Mithraic cave.
Not long after Howard moved to Sakkara, a group of drunken French tourists had tried to enter the Serapeum without the necessary tickets.
Of that legendary library, the most that survives today is a dank and forgotten cellar of the Serapeum, the library annex, once a temple and later reconsecrated to knowledge.