Discovery of an Ancient Timber Platform

Archaeologists have made a remarkable discovery in the heart of Scotland, unearthing an artificial timber platform that predates Stonehenge. This ancient structure is hidden beneath what appears to be an artificial stone island, offering a glimpse into the sophisticated engineering of prehistoric communities.

The find was made by researchers from the University of Southampton at Loch Bhorgastail on the Isle of Lewis. The site, known as a crannog, is an artificial island commonly found in Scottish lochs. What makes this particular discovery significant is its age—over 5,000 years old, making it older than the famous Stonehenge.

Although some wooden elements had been previously identified beneath the structure, the full extent of the timber foundation remained unknown until recent excavation work began. The team's findings, which reveal how the island looks both above and below the waterline as a unified structure, have been published in the journal Advances in Archaeological Practice.

Unveiling the Structure

During fieldwork at the site, archaeologists uncovered a layered construction of wood and brushwood beneath the stone surface, along with hundreds of Neolithic pottery fragments submerged in the surrounding waters. This discovery has provided valuable insights into the construction techniques and daily life of the people who lived in this area thousands of years ago.

Dr Stephanie Blankshein, a University of Southampton archaeologist, shared her excitement about the findings: "When we actually started excavating, we realised that it was actually this coherent, quite large timber structure that was under what you would see as the stone island today." She added, "So that was a big surprise, and that was in 2021 when we actually started digging down. Before that, we didn’t know. We just knew that there were pieces of wood sticking out and that there must have been some sort of structure there."

Advanced Techniques for Exploration

Working with experts from the University of Reading, the team used a technique called stereophotogrammetry to create 3D computer imagery from multiple 2D photos. This method allowed them to visualize how the island appears both above and below the waterline as a single continuous structure.

Dr Blankshein explained, "Through excavating and through the photogrammetry work that we did, we were able to build a picture of this coherent timber structure, not just bits of wood supporting a stone mound with a kind of timber platform underneath, but actually, the timber itself was the basis of the structure."

Overcoming Challenges in Shallow Water

Imaging in shallow water presents particular difficulties for archaeologists, as Professor Fraser Sturt, principal investigator and director of the Southampton Marine and Maritime Institute, explained: "Fine sediments, choppy conditions, floating vegetation and distorted or reflected light all hinder shallow water imaging. Photogrammetry is very effective in deep water but runs into problems at depths of less than a metre. This problem is a well-known frustration for archaeologists."

To overcome these challenges, the researchers developed a novel approach during their 2021 fieldwork. They used two compact, waterproof cameras with strong low-light performance and wide-angle lenses, mounted on a frame at a fixed distance apart to ensure precise image overlap.

Construction and Evolution of the Crannog

A diver manoeuvred the cameras through the water with centimetre-level precision, matching the accuracy of aerial drones. Dr Blankshein explained the photogrammetry work revealed that timber was the fundamental basis of the structure, rather than merely serving as a support for a stone mound.

The crannog began as a circular wooden platform measuring approximately 23 metres in diameter, covered with brushwood. Some 2,000 years later, during the Middle Bronze Age, additional layers of brushwood and stone were added, with further activity in the Iron Age roughly 1,000 years later.

A stone causeway, now submerged, connects the loch shore to the island, which was initially discovered in 2009. This ongoing research continues to shed light on the complex societies that once thrived in this region.