A flint church – the Parish Church of Saint Thomas, in Cricket Saint Thomas, Somerset, England. The height of the very neatly knapped flints varies between 3 and 5 inches (7.6 and 12.7 cm). Close-up of the wall of the Roman shore fort at Burgh Castle, Norfolk, showing alternating courses of flint and brick A typical medieval wall (with modern memorial) at Canterbury Cathedral – knapped and unknapped ("cobble") flints are mixed with pieces of brick and other stones Ruins of Thetford Priory show flints and mortar through the whole depth of the wall