Lake Kasumigaura
is an mountain located near Tsukuba, Japan. It is one of the most famous mountains in Japan, particularly well known for its double peaks, and . Many people climb the so-called "purple mountain" every year for the panoramic view of the Kantō plain from the summit. On clear days the Tōkyō skyline, Lake Kasumigaura and even Mount Fuji are visible from the summit. Japanese mountains are mostly volcanic, but Mount Tsukuba is non-volcanic granite and gabbro in origin. Renowned beautiful granites are produced in the northern quarries even today.