Senweseret I erected his pyramid in el-Lisht, about 1.5 kilometers south of Amenemhat I's. It was called  Senweseret looks down on  both lands. Limestone from the nearby quarries was the chief material used. A stone masonry framework supported the core, which rested on a foundation platform of stone blocks. The empty space inside the framework was filled with fragments of limestone, sand, and waste material from the construction site. The casing of blocks of fine white limestone was firmly anchored in a flat trench dyg around the pyramid's base.
The entrance to the underground part of the pyramid was in the pavement of the courtyard, in front of the middle of the pyramid's north side. A descending corridor, at the entrance was sheated in granite, and the barriers of enormous blocks of the same stone, weighting as much as 20 tons, is till there.  Arnold estimates that the burial chamber lay about 24 meters under ground level. The pyramid was surrounded by an inner perimeter wall, which build of limestone blocks. It was absolutly unique. On its inner side, at intervals of five meters, there were narrow panels decorated with images in bas-relief. Somewhat farther away was the outer perimeter wall, which surrounded the tombs of the members of the royal family as well.
The small cult pyramid, the last to be erected in a royal tomb complex, stood at the southeast corner of the pyramid.  The cult pyramid was plundered in antiquity and destroyed by stone thieves. It is most complicated , with two subterranean chambers and evidence of two or three phases of construction.The mortuary temple, which was called United are the [cult] places [of Senweseret], was also almost completely destroyed by stone thieves.

In the relatively extensive open space between the inner and the outer perimeter walls, nine small pyramid complexes were discovered, three on the south side and two each on the west, north and east sides of the pyramid. Ambrose Lansing earlier thought they were simple cenotaphs. The pyramids and mortuary temples each had the own perimeter walls. These complexes were other tomb shafts, reserved for the members of the royal family. So far, the pyramid complexes of Nofret I, Amenemhat I's daughter and consort of Senweseret I, and Itakaiet, probably king's daughter.The shaft in the center of the north side Nofret I's  pyramid (B) leads to a gently descending corridor paved with limestone. The corridor in turn leads to a chamber, lined with limestone, under the center of the pyramid. There was a hole for the sarcophagus and an unfinished niche for the canopic chest within this chamber, but the chamber appears to have never been finished, or used for a burial. 32 sided column inscribed with name of queen Itakaiet that was found within the ruins of next complex (C). The burial chamber in this pyramid was really only an extension of the entrance corridor, sealed with mortared limestone slabs. It is also questionable whether a burial took place in this pyramid as well, for there was no sarcophagus found within, and no visible hole large enough for thieves to have stolen it.
The shaft in the center of the north side leads to a gently descending corridor paved with limestone. The corridor in tern leads to a chamber, lined with limestone, under the center of the pyramid. There was a hole for the sarcophagus and an unfinished niche for the canopic chest within this chamber, but the chamber appears to have never been finished, or used for a burial. Thirty two fragments of sided column inscribed with name of queen Itakaiet that was found within the ruins. The burial chamber in this pyramid was really only an extension of the entrance corridor, sealed with mortared limestone slabs. It is also questionable whether a burial took place in this pyramid as well, for there was no sarcophagus found within, and no visible hole large enough for thieves to have stolen it.