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A large mudbrick structure dating to the 26th Dynasty, about 128 metres long, has been detected by Egyptian researchers beneath the Kom C mound at Buto (Tell el-Fara'in), in the northwest of the Nile Delta. Using satellite radar images and geophysical surveys, the team uncovered a complex buried for more than two millennia, without destructive excavation.
Buto, the Sacred City of the Cobra Goddess
Buto, today Tell el-Fara'in, is a vast tell, meaning a mound formed by the accumulation of successive occupation layers. For the ancient Egyptians, it was the sacred site of Wadjet, the cobra goddess of Lower Egypt, and one of the major religious cities of the pharaonic country.
Excavations carried out over several decades have mainly yielded remains from the Ptolemaic period, the Macedonian dynasty that ruled from 305 to 30 BCE, and from the Roman period. The deeper levels, located below the water table in waterlogged clay, have therefore remained largely inaccessible.
A Detection First Made From Orbit
The researchers turned to non-invasive methods. The European Space Agency's Sentinel-1 satellite produces radar images by sending microwave pulses toward the ground and measuring their reflection. These signals reveal subtle differences in moisture, elevation and reflectivity that can betray buried structures.
These images revealed an oval anomaly about 128 metres long and 62 metres wide beneath Kom C. A campaign of electrical resistivity tomography, with fifteen parallel profiles covering nearly 5,400 square metres, then helped refine its shape and depth.
Stacked Layers, from the Roman Era to the Saite Period
Between the surface and about 3 metres deep, investigators found Ptolemaic and Roman debris: displaced bricks, potsherds and fragments of broken limestone. These traces point to continuous occupation and successive rebuilding, with inhabitants often dismantling older buildings to reuse their materials.
Between 3 and 6 metres, a large mudbrick structure was identified. Dated to the 26th Dynasty, that is between 688 and 525 BCE, it was attributed to this period based on its stratigraphic position, the particular shape of its bricks and associated artefacts, supplemented by radiocarbon dating of organic material. According to the study, it could be a tomb, a priests' house or a sanctuary.
A Sand Foundation Against Delta Clay
The most striking feature lies between 6 and 7 metres below the surface: a thick layer of clean sand inserted beneath the walls. Nile Delta clay swells when it absorbs moisture and shrinks as it dries, which threatens heavy constructions. The Saite builders therefore prepared a sand cushion that spread the weight, allowed groundwater to drain and prevented the ground from deforming.
According to Abdelaziz Elfadaly, an associate researcher at the Egyptian National Authority for Remote Sensing and Space Sciences and co-author of the study, this layer "explains how these heavy structures survived" the high water table and shifting clay soils. A 3-by-3-metre excavation, taken down to 6 to 7 metres, confirmed the presence of thick walls resting on this sand.
Funerary Objects and Traces of Ritual
The excavation yielded ushabti and shabti figurines, small servant statuettes placed in tombs to accompany the deceased into the afterlife. A limestone altar, whose carved channels hold dried residues consistent with animal blood, suggests ritual offerings took place on the site.
The study also reports a faience baboon figurine associated with Thoth, god of wisdom. Published in March in the journal Acta Geophysica, the research illustrates how geophysics can complement traditional excavation at Delta sites.
Frequently asked questions
How can buried structures be detected from space?
Radar satellites such as the European Space Agency's Sentinel-1 send microwave pulses toward the ground and analyse their reflection. Variations in moisture, elevation and reflectivity can reveal buried walls or pits. Anomalies identified this way are then verified on the ground with geophysical surveys.
Where is the site of Buto?
Buto, today Tell el-Fara'in, lies in the northwest of the Nile Delta in Egypt. It is a tell, a mound built up by successive layers of habitation, long dedicated to the cobra goddess Wadjet.
Why was there a sand layer under the foundations?
In the Delta, clay swells and shrinks with moisture, which weakens heavy constructions. A clean sand bed spreads the weight, drains water and prevents mudbrick walls from dissolving in contact with the water table. The technique resembles modern foundations that distribute loads.
What was the Saite period of ancient Egypt?
The Saite period corresponds to the 26th Dynasty, between 688 and 525 BCE. It marked a revival of Egyptian art and architecture, with a return to older models. Remains from this era are rare in the Delta, which makes this discovery particularly valuable.
Sources
- Buried for 2,600 years beneath Nile mud, a massive ancient Egyptian complex was just found — from space — Live Science
Original summary written with the help of artificial intelligence from the sources cited, checked automatically, then translated from the French original. Information and quotations belong to their authors. Read the French original.
