Burnt mounds—enigmatic archaeological features scattered across Britain and Ireland—have long puzzled researchers. Composed of heat-shattered stones, flint, and charcoal, these sites are typically found in low-lying areas near rivers, marshes, and springs. Although once prominent in the landscape, centuries of agriculture have flattened most of these mounds, leaving behind only spreads of debris filling pits, troughs, and wells. Burnt mounds dating from prehistoric times, including the Beaker era, show clear signs of repeated use over decades or even centuries. Archaeological analysis indicates that stones were heated and rapidly cooled in water, but the purpose of this process has not been well understood. Theories have ranged widely from cooking and brewing to textile production, woodworking, and sauna-like bathing. However, new research into their likely use led by Cotswold Archaeology is shedding fresh light on this matter. Excavations at three sites—Marham Park in Fornham All Saints, as well as Laxfield and Hepworth—have produced compelling evidence suggesting that burnt mounds were primarily used for hide tanning. Two major findings support this interpretation. The bone preservation at these sites are predominantly from cattle, an animal closely associated with leather production. Flint tools at these sites are additional evidence in favour of the theory. Analysis of microwear shows patterns similar to scraping, piercing, and cutting dry hides, all processes involved in the tanning process. Chemical analysis has added to this evidence. Researchers found a “greasy fill” in one trough at Marham Park containing lipids derived from cattle and other animals. This residue strongly indicates processing of animal products—possibly associated with hide preparation. Environmental evidence is consistent with seasonal activity. Geoarchaeological surveys show Marham Park’s water sources were only reliable during certain times of the year, implying intermittent use. Pollen data for all three sites depict landscapes covered mainly by pasture, with slight seasonal fluctuations consistent with periods of intensified activity. This timing aligns with broader archaeological patterns, which suggest that burnt mound use often peaked in late summer or early autumn—coinciding with seasonal culling and the preparation of hides. The remote locations of these sites may also reflect the unpleasant odors associated with tanning, keeping such activities away from settlements. While debate continues, these findings offer one of the clearest explanations yet for burnt mounds. As excavation techniques and scientific analyses advance, archaeologists are steadily uncovering new insights into the practical realities of prehistoric life. Sources : Cotswold Archaeology