The whole group includes five and one-half large islands and nearly six hundred islets. The large island lying in the center constitutes the mainland; the island directly to the north is Hokkaidō (Yezo or Ezo), and that to the south, Kiushū; on the southwest of the mainland and east of Kiushū is Shikoku; and stretching in a northwesterly direction from Hokkaidō are the Chishima or Kuriles, while the chain of the Riukiū (Loochoo) Archipelago leads to Formosa. Floating, as it were, in the Sea of Japan are the islets of Sado, Oki, and Tsushima, the last lying only about fifty miles from the southern coast of Korea. Scattered in the Pacific Ocean, at a distance of nearly 500 miles from the southwest coast of the mainland, lies the Ogasawara group (Bonins). To these must now be added the recently ceded southern half of the Island of Sakhalin. Owing to the insular nature of the country, the area of the empire, exclusive of the half of Sakhalin, which is perhaps as much as 12,000 square miles, little exceeds 161,000 square miles, or slightly larger than the area of the British Isles. More than half of this superficies is comprised in the main island. The coastline of the fourteen larger islands and archipelagoes, again excepting Sakhalin, stretches to a length of 13,500 miles. Little indented, the coast along the Sea of Japan offers few bays or promontories; but the Pacific and the China Sea coasts are broken into innumerable capes and inlets, and abound in good harbors. The country is mountainous, and has little flat land. Two systems of mountain chains extend north to south and east to west, each having numerous branches. The highlands of the empire are the two provinces of Shinano and Kai, situated in the center of the main island. At the boundary of Kai and Suruga stands Fujisan, or Mount Fuji, capped with perpetual snows, its summit rising to 12,300 feet above the sea level. Its position as the loftiest peak in the country has been lost by the acquisition of Formosa, which contains Mount Morrison, now called Mount Niitaka, the altitude of which is not less than 14,200 feet. The mountains of the main island are for the most part volcanic, the active volcanoes numbering 170, and the ranges that comprise them stretch across the extent of the country. Mines and mineral springs consequently abound. Frequency of earthquakes also results from the abundance of volcanoes. Minor shocks average from thirty or forty to several hundreds annually, and of severe shocks history shows that there have been some two or three in each century, entailing sometimes a frightful destruction of life and property.