The Ravensberg Basin (German: Ravensberger Mulde) or Ravensberg Hills (Ravensberger Hügelland) is a natural region in the province of Detmold (Ostwestfalen-Lippe) in the northeastern part of the German state of North Rhine-Westphalia; small elements also fall within the neighbouring state of Lower Saxony. It is part of the lower Weser Uplands and includes the hilly basin country between the Wiehen Hills in the north, Lippe Uplands in the east, Teutoburg Forest in the south and Osnabrück Hills in the west.