Japan, a country of islands, extends along the eastern or Pacific coast of Asia. The main islands (sometimes referred to as the Home Islands), running from north to south, are Hokkaido, Honshu (or the mainland), Shikoku, and Kyushu. Naha on Okinawa, in the Ryukyu archipelago, is over 600 km to the southwest of Kyushu. In addition, about 3,000 smaller islands may be counted in the full extent of the archipelago that comprises greater Japan.

• Area: 377,835 km² (including 3,091 km² of territorial water)
• Major islands: Honshu, Hokkaido, Kyushu, Shikoku
• Coastline: 29,751 km
• Highest peak: Mount Fuji: 3776 m (12,385 ft)
• Lowest elevation: Hachinohe Mine -130 m (-426 ft)

Japan is the 18th most densely populated country in the world. However, about 73% of the country is mountainous, and unsuitable for agricultural, industrial, or residential use, due to the generally steep elevations, climate, and risk of landslides caused by earthquakes, soft ground, and heavy rain. This has resulted in an extremely high population density in the habitable zones that are mainly located in coastal areas.

Japan is situated in a volcanic zone on the Pacific Ring of Fire, at the juncture of the Philippine Plate, Pacific Plate, Eurasian Plate, and North American Plate. Frequent low-intensity earth tremors and occasional volcanic activity are felt throughout the islands. Destructive earthquakes, often resulting in tsunamis, occur several times each century. Twenty percent of the world's earthquakes magnitude 6.0 and higher are epicentered in Japan. The most recent major quakes include the 2004 Chuetsu Earthquake and the Great Hanshin Earthquake of 1995. Hot springs are numerous, and have been developed as resorts.

A map of Japan