Archaeologists uncover 5,000-year timber platform in Loch Bhorgastail Stone Island Excavation
Archaeologists in the loch bhorgastail stone island excavation found that the Loch Bhorgastail crannog on the Isle of Lewis was built on a large timber platform dating to between 3500 and 3300 BC. The site had long appeared to be a simple stone mound, but excavation exposed a coherent structure beneath the stone island.
Dr. Stephanie Blankshein of the University of Southampton said, "When we actually started excavating is when we realized that it was actually this coherent, quite large timber structure that was under what you would see as the stone island today." The platform was described as 23 meters across and topped with brushwood.
Loch Bhorgastail Crannog
The work pushes the island's construction back into the Neolithic period and shows that timber, not stone alone, carried the earliest structure. The team mapped the crannog above and below the waterline using shallow-water photogrammetry, two small waterproof low-light cameras mounted on a frame, and a diver who moved the frame with centimeter-level accuracy.
Professor Fraser Sturt, principal investigator and director of the Southampton Marine and Maritime Institute, described the limits of traditional photogrammetry in shallow water as a "well-known frustration for archaeologists." The methodology was published in Advances in Archaeological Practice.
Outer Hebrides Crannogs
Later activity at the site added a layer of brushwood and stone during the Middle Bronze Age, and further activity took place in the Iron Age. Hundreds of pieces of Neolithic pottery have also been recovered from the loch bed around the island, and a now-submerged stone causeway once linked it to the shore.
The Loch Bhorgastail result adds to a wider pattern in the Outer Hebrides, where archaeologists estimate about 170 crannogs and several sites have produced large collections of near-complete Neolithic vessels. For readers tracking the site, the key change is simple: Loch Bhorgastail is no longer just a stone mound on the map, but a much older timber-built island with a later stone and brushwood history layered on top.
