Ninomegata Maar With a diameter of 400m and a depth of 11.8m, the freshwater lake of Ninomegata Maar is one of the Oga-megata Maars. A volcano formed by a single eruption is called a monogenetic volcano, and the Oga-megata Maars are an example of this type. West Coast Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)
