Green Castle, Portknockie
Green Castle is a naturally defended rocky outcrop in the village of Portknockie in Moray, Scotland, that was occupied successively by small promontory forts of the Iron Age and Pictish periods. The site forms a rocky headland long and wide, surrounded by steep cliffs rising high above the sea. The site was extensively excavated between 1976 and 1982. During the Iron Age a single palisade was built to protect the headland at its landward side. Traces of the slot created by these timbers, together with an Iron Age sherd and pits have been excavated. This occupation period  produced evidence of metalworking, including fragments of moulds, furnaces, hammerstones and whetstones. Ard marks over the upper surfaces of Iron Age archaeological layers suggest that the site was then used for agriculture before being reused for defensive purposes during the Pictish period. A new timber palisade backfilled by beach cobbles marked a first phase of Pictish activity on the site. The fort was then extensively rebuilt in the 7th and 8th centuries – possibly in response to the start of Norse raids on the northern Pictish Kingdom of Fortriu – with a more sophisticated structure of timber-laced stone ramparts protecting a  central stone hall. These defences were later destroyed by fire, possibly the result of a Viking siege. During the 19th century the site was used for fish drying and most of the area was covered by low stone platforms.