There are two unfinished monuments about 5km to the south of the Dahshur necropolis near the village of Mazghuna, known as the Mazghuna North and South Pyramids. Although the names of the rulers who built these pyramids is by no means certain, they have been attributed by many archaeologists to the Middle Kingdom reigns of Amenemhet IV and Sobeknefru.

The South Pyramid at Mazghuna is often attributed to Amenemhet IV, the last king of Dynasty XII and the son of Amenemhet III, although no names have been found in the complex. The reason for the attribution is based on stylistic grounds - the layout of the substructure and burial chamber resembles that of Amenemhet III's pyramid at Hawara in the Faiyum. Amenemhet IV completed his father's temples at Medinet Madi and probably also built the temple at Qasr el-Sagha, but his reign was short and there is no certainty about the location of his burial place. Mazghuna South Pyramid was investigated in 1910 by British archaeologist, Ernest MacKay. Today, only the ruined mudbrick core of the pyramid remains, with no trace of casing, suggesting that the superstructure was left unfinished.

The pyramid's entrance opens in the centre of its southern side, with a descending staircase in a corridor flanked by side ramps. As it levelled out the passage was blocked by a barrier slab of granite, with two more blocking slabs at further points. The position of the burial chamber was beneath the vertical axis of the pyramid, after turning three times in a series of short corridors. A single massive block of red quartzite fills the burial chamber, with a trench for the coffin and a carved recess for the canopic jars - a similar arrangement and closing mechanism to Amenemhet III's burial chamber at Hawara. The ceiling was probably supported by vaulted limestone blocks.

The whole complex was surrounded by a wavy perimeter wall built from mudbrick, with an entrance at the south-east corner. The mudbrick mortuary temple, consisting of a large chamber or court with magazines on either side, was attached to the east side of the enclosure wall, rather than to the pyramid itself. There is no trace of a causeway or valley temple.

Immediately to the north of the previous pyramid, the second pyramid at Mazghuna is also of uncertain origin, but is sometimes attributed to Amenhotep IV's successor, possibly his sister (and perhaps wife), Queen Sobeknefru (Nefrusobek) who ruled for about three years in her own right. Sobeknefru was the first definitely attested female pharaoh (although Queen Nitiqret may have ruled in Dynasty VI). The North Pyramid was planned to be larger than its neighbour and attributed to the queen solely on structural grounds.

The superstructure of the pyramid seems never to have been begun, but the plan of the underground chambers is more advanced than that of Amenemhet IV. The entrance to the substructure is to the east of the northern side of the base and has a descending staircase which turned several times through various chambers fitted with blocking plugs before reaching the burial chamber. The burial chamber once more contained a huge quartzite block with carved-out spaces for the coffin and canopic jars. Although the sarcophagus block was smoothed, plastered and painted red, there was never any burial here.

Neither was the rest of the pyramid complex completed, although mudbrick walls of a causeway were found to approach the structure from the east. It was investigated in 1910 by Ernest MacKay.