In the neighborhood of ~ ~, Nagasaki, over the celebrated solfataras of Unzen-take KlilshIiI (called also Onsen) stands an extinct volcano, whose summit, Fugen-dake, is 4865 ft.
The northern part is occupied by a steaming lake, while the southern part contains numerous solfataras and boiling springs.
Fergusson Island clearly shows remains of extinct craters, and possesses numerous hot springs, saline lakes and solfataras depositing sulphur and alum.
Fine lakes and waterfalls, innumerable pools, in temperature from boiling-point to cold, geysers, solfataras, fumaroles and mud volcanoes still attract tourists in large numbers.
The boron contained in solution in the salt lakes has very probably been supplied by hot springs and solfataras of volcanic origin, such as those which at the present day charge the waters of the lagoons in Tuscany with boric acid.