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.