The well-preserved concentration of late 18th century and 19th century shaft mounds at Dewley Pits represent a nationally rare form of coal mining landscape. 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. The largest area of the Dewley Pits Scheduled Ancient Monument includes the earthwork remains of Lady Pit, which was mined in the later 18th century and early 19th century. It includes a large sub-circular shaft mound measuring approximately 50 metres by 40 metres, and other features associated with the operation of the shaft probably survive as buried remains. To the west of the shaft mound are the well-preserved remains of a wagonway embankment running north-south, which is linked to Lady Pit by two short branch lines. Both the shaft mound and the wagonway overlie an area of ridge and furrow cultivation, which illustrates the impact of the Dewley Pits on the earlier rural landscape. The earthwork remains 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. Evidence of horse powered pit-top features (man-riding, coal winding and pumping) are expected to survive with possible remains of buildings and potentially important underground workings.