Q:Leiblach - The Leiblach is a 33 km long tributary of Lake Constance and the Rhine River. Its source is near the German municipality of Heimenkirch flowing to the southwest. Near the Austrian town of Hohenweiler the river joins a small tributary the Rickenbach. This tributary forms a part of the Austrian-German border and below the confluence the border continues to follow the Leiblach eventually emptying into Lake Constance between the German town of Lindau and the Austrian town of Lochau. Given a choice of categories company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, the text refers to which one?
A:
Natural Place