The Stokenchurch Gap, also known as the Aston Rowant Cutting or Aston Hill cutting (from the nearby village of Aston Rowant), or locally "The Canyon" is a steep chalk cutting, constructed through the Chiltern Hills in Oxfordshire, England during the early 1970s for the M40 motorway. It is 1,200 metres long and a maximum of 47 metres deep, and is located approximately eight miles (13 km) from High Wycombe and close to the village of Stokenchurch. Despite the names, the cutting is in the parish of Lewknor rather than Aston Rowant or Stokenchurch.