The Main River is not only the longest contained in river in Germany so perhaps unsurprisingly important in the brewing world as a source of water and transportation. There are many in Franconia, where the it originates and a particularly scenic stretch is in Lower Franconia. Three towns to seek out for beer on this route are Marktheidenfeld (Martinsbräu), Wertheim (Spessart) and Lohr am Main (Keiler Brauhaus).
