Castle Greg is the archaeological remains of a Roman fortlet near Camilty Plantation, approximately three miles south-east of West Calder, West Lothian, in Scotland. The site is less than an acre in size, and lies just off the B7008. It is one of the best preserved Roman earthworks in the country and was first excavated in the 19th century by Sir Daniel Wilson, the interior excavation having taken place in 1852. The name Castle Greg is possibly derived from the Roman name Camulosessa Præsidium, from nearby Camilty, itself derived from Camulos Tref – literally, village of Camulos.