Wikipedia
Hügelland is a type of landscape consisting of low, rolling hills whose topography or surface structure lies between that of a lowland region (plains or river terraces) and that of a more rugged hill range or low mountain range. The term is German and has no exact equivalent in English, but is often translated as "hill country", "hilly terrain", "upland(s)" or "gently undulating" or "rolling country", or "rolling countryside". It is derived from Hügel, a low hill or hillock and appears frequently as a proper name for this type of terrain.
The term Hügelland is not unambiguously defined, even in German. For example, on the plains of North Germany, Poland or Hungary it may be applied to terrain with a height variation of just 50 metres, whilst in the Alpine Foreland or in the Pre-Alps it might refer to terrain with a height difference of at least 100–200 metres. On the other hand, some scholars prefer to define Hügelland by its height above sea level; for example, applying it to terrain between 200 and 500 metres above sea level.