This separate structure lies behind the temple of Seti I, to the southwest. Its purpose is unclear and its architectural features are unique. It has variously been called a cenotaph, though it bears no resemblance to such a funerary structure, and a mortuary temple, though there is no other like it. In fact no other structure was surrounded by water.
The ante-chamber (4) is decorated with scenes from the mortuary literature, relating to the journey through the under-world (page 87). The transverse chamber to the east (5) is also decorated with scenes from the mortuary literature; that to the west (6) has an arched ceiling and some badly damaged scenes of the cosmogony, featuring the sky-goddess Nut, the earth-god Geb, and Shu the god of the atmosphere.