Osireion

The Osireion is part of the Temple of Seti I's complex and lies centrally behind its main part along an east–west axis. It may have been built to resemble the tombs in the Valley of the Kings. Most of its structure would have been subterranean, built at a considerably lower level than the foundations of the Temple of Seti I, and most of the roof has been lost. An entrance tunnel, 69 metres (226 ft) long and stone lined, runs along a north–south axis behind the central hall.

The central hall is constructed with very large stone blocks, with a limestone interior and sandstone facing. The roof would have been formed of large granite beams. The hall contains a stone-paved 'island' in the centre surrounded by a channel of water, the depth of which is yet to be determined; the water is at least 10.4 metres (34 ft) deep and connects to an underground water source. There are 17 small chambers in the hall's walls, and behind the wall opposite the entrance there is a 'sarcophagus chamber'.

Strabo visited the Osireion in the first century BCE and described, at Abydus, a royal building of solid stone and a fountain lying at a great depth, reached down vaulted galleries made of monoliths of surprising size and workmanship. The subterranean water basin was consequently named Strabo's Well by modern excavators. Strabo suggested that the structure might have been built by Ismandes, or Mandes, the purported builder of the Labyrinth at Hawara, and his uncertainty about its origins suggests that these were already unknown by the time of his visit.

The Osireion was rediscovered by the archaeologists Flinders Petrie and Margaret Murray, who were excavating the site in 1902–1903.