Headed due west from the temple built within the Upper Necropolis, we come to a small elevation of land, at a distance of approximately 1.5 km. This is the Osireion, a subterranean temple dedicated to Osiris. The temple has a series of galleries or catacombs dug into the rock. It has one principal entrance and two secondary entrances. One of the galleries contains a prone statue of Osiris, measuring more than three metres in height. Some of the galleries also contain a series of niches built into the walls on both sides, for the burial each year of an earthen statuette of Osiris that had been the principal object of the mystery rite of the god’s resurrection in the previous year. We know that this type of temple existed in other places in Egypt, but the Osireion of Oxyrhynchus is currently a unique monument due to its unique state of preservation.
The lintels of the niches bear a series of hieratic inscriptions that provide corroborative data on the burial of each statue. The inscriptions extend from the reign of Ptolemy VI Philometor to the joint reign of Ptolemy X Soter II and Cleopatra III. All of these dates correspond to the second half of the second century BC. In addition, the inscriptions provide the name of the temple, Per-Khef. Thanks to the hieroglyphic inscriptions in the Saite tombs in the Upper Necropolis, we know that this temple, Per-Khef, already existed in the Saite period.
The exterior part of the temple is completely demolished, although the rectangular outline of the temenos surrounding the sacred enclosure survives. When the mission discovered the Osireion and began work in 2000 and 2001, the researchers found that the name Per-Khef had already appeared on blocks of stone surfacing on the antiquities market in the nineteen-fifties. Today, some of these blocks are housed in museums in Leiden (the Netherlands) and Besançon (France), while the majority reside in private collections in Switzerland. The reliefs on these blocks depict divine triads in which Taweret appears in the form of a woman, as a secondary divinity associated with Osiris. The inscriptions mention the name of the temple, Per-Khef, and the names of the kings Alexander IV of Macedonia, who was the son of Alexander the Great; Ptolemy I Soter, and Ptolemy II Philadelphus. This makes it clear that the Osireion of Oxyrhynchus was the object of restoration work in the time of the early Ptolemies. It also appears that the superstructure of the temple was dismantled by looters who sold the blocks of stone on the antiquities market.