The A66 has been a routeway of significance for at least 2000 years, linking the east and west of the country by the Stainmore Pass. Archaeological excavation ahead of the upgrading of the A66 to dual carriageway, between Greta Bridge and Scotch Corner, provided an important opportunity to investigate the development of the landscape. The archaeological remains discovered, described in Scots Dyke to Turnpike: The Archaeology of the A66, Greta Bridge to Scotch Corner, range in date from early prehistory to the 19th century, and particularly from the Iron Age and early Roman period. One of the most significant results was the important new dating evidence for a section of the Scots Dyke, a substantial linear earthwork between the Rivers Tees and Swale. It has been dated to the early-middle Iron Age, which places it within the wider Iron Age and Roman landscape revealed by the road improvement scheme. This may indicate that it was related in some way to the Iron Age tribal centre at nearby Stanwick.