Marimo: Lake Akan in Japan is most noted for housing these Moss Balls. The ones in Lake Akan are the most superb samples of Marimo that can reach diameters of 20 to 30 centimeters. The following is a photo of my Marimo (I have one large and two small ones). For even more information on the history and how they become so round please take a look at this website: http://www.marimo-web.org/en/index.html