A few miles west of the Nile and just below the tip of its delta lies the modern Sakkara, site of the necropolis of ancient Memphis, center of Lower Egypt from the days of the pharaohs through the time of Egypt's Roman conquerors. The sacred ibis, the graceful black and white bird in which the god Thoth showed himself, no longer visits the Nile at Memphis, but when the Ptolemies and their Roman successors drank from the holy river, the god's bird still came to its banks in great plenty. So huge were its flocks that those who wished to honor Thoth with mummies of his bird were able to prepare thousands of such offerings every year, thus proving their piety in a cult of the ibis, just as devotees of Osiris-Apis or Sarapis worshipped their god in the bull cult of the great Serapeion, the temple that dominated the landscape of Ptolemaic Memphis. Many gods dwelled in the precincts of the Serapeion: Isis of the hundred names, whose worship had already begun to spread from Egypt through the Mediterranean basin; Imhotep or Imouthes, a god of healing whom the Greeks called Asklēpios; and Thoth, god of the moon and messages and writing, Hermēs to the Greeks, and like Hermes the guide of dead souls. In Sakkara, north of the Serapeion proper, archeologists have uncovered structures built for Thoth's ibis, a lunar bird of the night, and also for the hawk of Horus, a solar daytime bird. In these buildings attendants of the sacred birds hatched, reared, venerated and eventually mummified them for burial in urns.