While the Northrhine-Westphalia region is dominated by big cities (Ruhrgebiet), there is one region to the southeast around the cities of Arnsberg, Paderborn and Soest that is dominated by hills, woodland, lakes, and generally more rural in character: The Sauerland.
It is very popular for hiking (the "Rothaarsteig" is a worthwhile hiking trail; another popular hike goes to the highest elevation of the region, the "Kahler Asten"; another around the "Bruchhauser Steine", unusual stone formations). The small villages are often dominated by half-timbered houses - a good example would be Schmallenberg or Arnsberg. Lots of castles (or castle ruins) too, like the castles in Altena and Schellenberg. The Atta Cave is another major attraction of the area.