A strange stone monument stretching across the desert has given archaeologists a rare glimpse into how prehistoric communities in the Western Sahara buried their dead. Built from limestone slabs and marked by two long, antenna-like extensions, the structure had remained difficult to date and even harder to interpret. Now, a new excavation has established that the monument was used for burial roughly 4,400 years ago.

The monument was found at Wadi Lawash el Telli, on the eastern edge of the Sluguilla Lawash rock-art site in northern Western Sahara. As reported in Archaeology Magazine, researchers dated the burial to between about 4,417 and 4,100 calibrated years before present, providing the first absolute chronology for an antennae tumulus in the Atlantic Sahara.A monument unlike ordinary tombsThe structure belongs to a distinctive class of prehistoric stone monuments known as antennae tumuli.

At Lawash el Telli, an oval mound forms the main burial structure, while two elongated lines of stones extend eastward from either side, creating the unusual appearance that gave the monument its name. As reported in the African Archaeological Review, the entire structure measures about 54.5 metres in length, with the central mound measuring approximately 12.5 metres long and 10 metres wide and rising less than three metres above the surrounding gravel plain.

The construction involved local Devonian limestone which was laid down flat on the surface without the use of mortar. Most of the stones had dimensions of less than one metre, indicating that the monument could have been erected by a small number of people without having to establish infrastructure for stone extraction and transportation. The two stones are aligned at about 102 degrees from north. This has already generated theories about the possibility of an astronomical connection for some Saharan monuments.

However, the researchers have not established that the Lawash el Telli structure served any astronomical purpose, making its funerary role the clearest interpretation supported by the excavation. The monument also stands in a landscape rich in prehistoric activity. Nearly 1,140 engraved rocks have been documented along about 27 kilometres of the nearby wadi, containing more than 2,000 individual figures. The carvings include animals such as cattle and ostriches, offering evidence of a very different Sahara from the extremely dry environment seen today.A burial hidden beneath the stonesArchaeologists excavated the monument between April 5 and 8, 2018.

Because of the site's remoteness and difficult conditions, they investigated only part of the mound, leaving the remainder intact for future work. Beneath layers of loosely arranged stones, the team discovered a second structure made from larger limestone slabs. Under this protective covering lay the remains of a single individual. The burial showed no evidence of later disturbance or reuse, allowing researchers to study the monument in a relatively undisturbed context.

The deceased had been laid out supine, with the head oriented south and the feet pointing west. As the skeleton had not been preserved well, the sex could not be established, but based on the dental wear, the individual would have been between 25 and 35 years old. There were few objects found buried with the person; only four beads, made of ostrich eggshell, in a ring-like shape. Beads such as these have been found at several prehistoric sites in the Atlantic Sahara; thus, they do not reveal much about the culture to which this person belonged.

Two grains of pine pollen were also found in the sediment sample. Dating a long-standing archaeological mysteryThe biggest breakthrough came from scientific dating. Initial attempts in 2018 failed because the bones no longer contained enough collagen for conventional radiocarbon analysis. Researchers returned to the remains in 2025 and instead analyzed the mineral component of the bone. The two samples produced closely matching dates. One fragment of the humerus dated to 4,417–4,160 calibrated years before present, while a femur fragment produced a range of 4,405–4,100 years. When combined, the results place the burial mainly between about 4,407 and 4,230 years ago.

The researchers noted that the monument dates to the later part of the region's Late Neolithic period, when communities were already building several forms of stone funerary structures. The evidence suggests that antennae tumuli overlapped in time with crescent-shaped burial monuments, indicating that different monumental traditions existed alongside one another.

Dating offers an important timeline for a region where the dating of prehistoric stone structures has traditionally been problematic. Archaeological excavations elsewhere have also found that the reconstruction of prehistoric Saharan societies was hindered by the poor preservation of human remains and datable artifacts. As things stand, the 4,400-year-old tomb does not explain why the ancient builders added the two long “antennae” stones. The mysterious stone formation from one of the driest regions on Earth has finally been shown to have been part of a prehistoric funerary tradition.