The earthwork remains of the shaft mound and spoil heap of the mine formerly known as Brass Pit survive on this site. Coal extraction began here in 17th century and the Dewley Pits continued to be worked into the 19th century when they were the workplace of George Stevenson during the early part of his career. Andrew Pit survives as a large shaft mound with its associated spoil heap. The coal mining remains at Dewley Pits survive well and represent a remarkably well-defined concentration of late 18th century and 19th century shaft mounds. The earthworks overlie remains of earlier ridge and furrow cultivation, which illustrates the impact of the Dewley Pits on the earlier rural landscape. Most significantly, they provide information for the historical and technological development of coal mining in this area, contributing towards the understanding of the transition from small scale, low investment mining to the more capital intensive, nucleated mines that emerged in the late 18th century in an area of arable fields. In this respect they are of national importance.