Radiocarbon dating of burnt twigs found inside a broch at Clachtoll in Assynt (Highland, Scotland) suggest its interior remained untouched after it was built in the Iron Age. Brochs were often modified during later periods of use. One at Nybster in Caithness has evidence of possible Pictish and medieval occupation. The dating of twigs possibly used for woven mats points to the Assynt site remaining unaltered until it collapsed.
     Archaeologists involved in a community project called Life and Death in Assynt's Past had expected the burnt wood to date from 300 to 1000 CE, during the building's final phase of occupation. However, tests at AOC Archaeology's laboratory in Midlothian dated it to 111 BCE and 55 CE, suggesting generations of families left the interior unaltered from the time it was created. A spokeswoman for the project said: "The possibility that we have a genuine Iron Age broch interior, untrammelled by later modification of admixture, is very exciting indeed."
     Built of stone, circular tower-like brochs were impressive homes in some of Scotland's Iron Age communities. The broch at Clachtoll was built using stones weighing up to 100kg each.

Edited from BBC News (14 November 2011)