El Lahun (Arabic: اللاهون El Lāhūn alt. Illahun, Lahun, or Kahun [the latter being a neologism coined by archaeologist William Matthew Flinders Petrie]) is a village in Faiyum, Egypt. Associated with the pyramid of Senusret II (Greek: Sesostris II), it is located near the modern village, and is often known by the same name. Also nearby is the pyramid itself, known as the Pyramid of Lahun. The ancient name of the site was rꜣ-ḥn.t, literally, "Mouth (or Opening) of the Canal"), realized in the Fayyūmic dialect of Coptic as ⲗⲉϩⲱⲛⲉ Lehoune).
Like the other Twelfth Dynasty pyramids in the Faiyum, the Pyramid of Lahun is made of mud brick, but here the core of the pyramid consists of a network of stone walls that were infilled by mud brick. This approach was probably intended to ensure the stability of the brick structure. Unusually, despite a Pyramid Temple on the east side, the entrance to the pyramid is on the south. The archaeologist Flinders Petrie nevertheless spent considerable time searching for it on the east side. He discovered the entrance only when workmen clearing the nearby tombs of the nobles discovered a small tunnel at the bottom of a 40-foot shaft, which led to the royal burial chamber. Evidently the original workmen on the tomb had used their legitimate activity as a cover for digging this tunnel, which enabled them to rob the pyramid. Once he was in the burial chamber, Petrie was able to work backwards to the entrance.
The pyramid stands on an artificial terrace cut from sloping ground. On the north side eight rectangular blocks of stone were left to serve as mastabas, probably for the burial of personages associated with the royal court. In front of each mastaba is a narrow shaft leading down to the burial chamber underneath. Also on the north side is the Queen's Pyramid or subsidiary pyramid.