About 3,000 smaller islands are included in the archipelago. In total land area, Japan is slightly smaller than California . Since so little flat area exists, many hills and mountainsides are cultivated all the way to the top. As Japan is situated in a volcanic zone along the Pacific deeps, frequent low-intensity earth tremors and occasional volcanic activity are felt throughout the islands. Destructive earthquakes occur several times a century.
Hot springs are numerous and have been developed as resorts.
Temperature extremes are less pronounced than in the U.S. since no part of the interior is more than 100 miles from the coast. At the same time, because the islands run almost directly north-south, the climate varies. Fukuoka, on the island of Kyushu, has a climate similar to that of Washington, D.C. with mild winters and short summers. Okinawa is subtropical.