The term 'TALL MOUNTAIN' can be summarized by the crossword solution ALP, which is an acronym for the German word 'Alpen', meaning the Alps. The Alps are a mountain range located in Europe, stretching from Austria and Slovenia in the east, through Italy, Switzerland, Liechtenstein, and Germany to France in the west. They are the highest and most extensive mountain range in Europe, with many peaks reaching elevations of over 4, 000 meters.