Long before wooden beds or woven mattresses, humans were already paying close attention to where they slept. New research from Border Cave, on the border of South Africa and Eswatini, is shedding light on a surprisingly familiar part of daily life that has rarely survived in the archaeological record.
Sleep leaves behind very little evidence. Grass, leaves, and other plant materials usually decay long before archaeologists can examine them, making ancient bedding incredibly difficult to identify. That is why discoveries linked to prehistoric sleeping areas are exceptionally rare.
A study published in 2026 in the Journal of Archaeological Science reveals that the cave’s occupants repeatedly built and renewed plant bedding between 200,000 and 43,000 years ago. By laying grass over layers of ash, they created and maintained dedicated sleeping spaces.
Ancient Soil Revealed Six Types of Prehistoric Beds
Border Cave has been excavated for almost 90 years, but researchers are still uncovering new details about the people who once lived there. Located in the Lebombo Mountains, the site preserves an archaeological sequence stretching from the Paleolithic to the Iron Age.
By examining sediment under a microscope, the research team identified six different microfacies, each representing a distinct type of bedding. These microscopic layers revealed that the cave’s occupants did not prepare their sleeping areas in exactly the same way throughout its long history.
The beds were made mostly from grasses belonging to the Panicoideae subfamily, along with reeds spread directly on the ground. Three of the youngest bedding types have no known equivalent in previously published research. The others resemble bedding discovered at the nearby South African sites of Sibudu and Diepkloof, although researchers noted several differences between them.
“These differences could reflect inter-site variations in bedding construction and/or maintenance or be due to the plant material utilised,” wrote the authors.
Ash Was More Than Just The Remains Of A Fire
The grass was not placed directly on the cave floor. Instead, archaeologists found thick layers of ash beneath the bedding throughout the archaeological sequence, showing that this was a repeated feature of the sleeping areas over thousands of years.
The study explains that the ash helped keep the bedding dry and warm while also discouraging crawling insects. Researchers also found signs that old bedding was regularly burned before fresh plant material was added on top of a new layer of ash.
This cycle of removing worn bedding and replacing it with fresh grass was repeated over thousands of years. It shows that maintaining sleeping areas was part of everyday life for the cave’s occupants rather than an occasional activity.
The Way People Slept Changed Over Time
Not every bed looked the same. The researchers found noticeable differences in burned plant remains and in the distribution of phytoliths, tiny mineral particles that plants leave behind after they decay. These subtle variations revealed that the bedding was not created in a single way but was repeatedly rebuilt and modified over thousands of years, reflecting changing materials, maintenance practices, and possibly different uses of the sleeping areas.
The youngest bedding layers, dating from 60,000 to 43,000 years ago, were less fragmented, less burned, and showed fewer signs of trampling than older examples. Those differences point to changes in how the sleeping areas were prepared or used over time.
The preserved bedding spans roughly 161,000 to 43,000 years ago, while some of the deposits linked to these occupations date back nearly 200,000 years. Throughout that period, laying fresh grass over ash remained a consistent feature of life inside the cave. Three bedding types still have no known equivalent elsewhere, giving archaeologists another piece of the puzzle as they continue studying one of Africa’s most important prehistoric sites.
