The archipelago of Japan contains over 4,000 islands stretching along the Pacific coast of East Asia, with four major islands (sometimes referred to as the "Home Islands"): Hokkaido, Honshu, Kyushu and Shikoku.
Honshu is the main island of Japan, and largest at 810 miles (1,300 km) in length. Dominated by mountains and volcanoes, the massive earthquake of March 2011 moved Honshu 7.9 ft (2.4 m).
The second largest, Hokkaido, is also the northernmost of Japan's islands; while on the other end, Kyushu is the most southwesterly. Shikoku is the smallest and least populous of the four main islands.
A long ridge of rugged mountains runs through the heart of Japan, punctuated by steep tree-lined slopes, and deep valleys on the Pacific Ocean side, and lower hills and mountains along the Sea of Japan side.
The main interior mountain ranges include the Akaishi, Hido and Kiso, where elevations typically exceed 9,800 ft. (3,000 m). The country's highest point, Mt. Fuji, southwest of Tokyo, is a dormant volcano that rises 12,388 ft. (3,776 m).
The islands of Japan are located on the Ring of Fire, and as a result suffer from frequent, violent earthquakes and some serious volcanic activity. There are a total of 108 active volcanoes within Japan's archipelago, most of which provoke devastating earthquakes and tsunamis several times every century.
A small series of plains are situated along the coastal areas. A notable number of (very short) rivers flow briskly down the mountains into the coastal areas. The largest river in Japan is the Shinano.