The Layer Pyramid (known locally in Arabic as el haram el midawwar, is a ruined step pyramid dating to the 3rd Dynasty of Egypt (2686 BC to 2613 BC) and located in the necropolis of Zawyet El Aryan. Its ownership is uncertain and may be attributable to pharaoh Khaba. The pyramid architecture, however, is very similar to that of the Buried Pyramid of king Sekhemkhet and for this reason is firmly datable to the 3rd Dynasty. The pyramid was excavated at the beginning of the 20th century by two different teams who reported conflicting estimates regarding its size and number of subterranean chambers. No artefacts were found over the course of the excavations, and no trace of a burial could be found. For this reason, it is unclear whether the pyramid was used to bury a pharaoh or was abandoned following the premature death of the king. At the time of its construction the pyramid was surrounded by a necropolis housing large mastabas belonging to the high officials of the 3rd Dynasty state. A mortuary temple was built on the eastern side of the pyramid and a valley temple was possibly located several hundred metres from it. Nowadays, the pyramid is located within the confines of a restricted military area, barring modern excavations of the site.
The Layer Pyramid was first examined, and its surroundings explored in 1839 by John Shae Perring. Soon after, in 1848, the pyramid was identified as such by Karl Richard Lepsius, who listed it as number XIV in his pioneering list of pyramids. Around 40 years later, in 1886, Gaston Maspero unsuccessfully searched for the entrance of the subterranean passages of the pyramid, which was discovered in 1896 by Jacques de Morgan. The latter undertook excavations of the pyramid but stopped after clearing the first few steps of the descending stairway. Further investigations were then performed in 1900 by Alessandro Barsanti, who uncovered the vertical access shaft leading to the burial chamber. Barsanti, seeing that several corridors and chambers were seemingly unfinished and that all were completely devoid of artefacts, deemed that the pyramid had never been used. Shortly after, in 1910–1911, George Reisner and Clarence S. Fisher worked on the site, excavating the north and east exteriors of the pyramid as well as the cemeteries surrounding it.
The Layer Pyramid has a square base whose side is about 84 m (276 ft) long, slightly smaller than the step pyramids of Djoser and Sekhemket. Based on the dimensions of the pyramid of Djoser, the egyptologist Jean-Philippe Lauer estimated that the layer pyramid was originally planned to comprise five steps and would have reached c. 42–45 m (138–148 ft) in height. Today, only two of these steps remain, reaching a height of about 17 m (56 ft). The current ruined state of the pyramid allows a view of its core, which is an 11 m2 (120 sq ft) pyramidal mound made of poor-quality rough stone blocks taken from the local bedrock. This core is surrounded by a 2.6 m (8.5 ft) thick casing of the same masonry. This is in turn surrounded by 14 layers of mud bricks bonded with clay mortar and disposed almost vertically, with an inward inclination angle of 68°. Just as the inner-most stone casing of the pyramid core, each mud brick layer is 2.6 m (8.5 ft) thick.