Built by the Middle Kingdom pharaoh Senwosret II (1897–1878 BC, also called Sesostris II), this mud-brick pyramid's outer casing was stolen in antiquity. (The pyramid is 347 feet square, and the original height was 157 feet.) A natural knoll of rock was used as a central core for the pyramid, and stone walls were built radiating out from it; the interstices were filled with mud brick before finally being cased with fine limestone. This gives the illusion that this was
a true pyramid completely built of stone. Lahun was the first pyramid to abandon a single northern entrance in favor of two entrances on the south side. Its underground chambers (inaccessible) contain dead ends and twists and turns to disguise the whereabouts of the granite burial chamber, which when discovered in modern times contained an empty red granite sarcophagus and an alabaster offering table. The devious layout of the substructure, along with the transfer of the entrance from north to south, was perhaps the result of a quest for greater security for the place of burial.