Torpenhow Hill is an unassuming hill in the Lake District, England - notable, however, for its name. You see, tor means hill. Pen means hill. How (or howe) means hill. Thus, Torpenhow Hill actually trasnslates as Hillhillhill Hill.
It is believed that succesive inhabitants of the hill all took the last occupants' name for it, and, not understanding what that name actually meant, added their own word for 'hill'. There are many other examples of this worldwide, such as 'Lake Loch Ness', the Sahara Desert (the Desert Desert) and the Sierra Nevada Mountains (the Snowy Mountains Mountains).
Don't go around pedantically correcting people yet though - adding the English word at the end easily helps identify what kind of geographical feature these things actually are. A similar phenomenom exists in such tautological phrases as "personal PIN number"; yes, I know it comes out as "personal Personal Identification Number number", but it helps clear any confusion between PINs and pins, or pens, pans, pines, pains, or porn (depending on accent).