Description & Facts: Nagasaki is the capital and the largest city of Nagasaki Prefecture in Japan. Nagasaki was founded by the Portuguese in the 16th century. It was formerly part of Nishisonogi District. It was a center of Portuguese and European influence in the 16th through 19th centuries. Nagasaki became a major Imperial Japanese Navy base during the First Sino-Japanese War and Russo-Japanese War. During World War II, the atomic bombings of Hiroshima and Nagasaki made Nagasaki the second (and last, as of 2009) city in the world to be subject to nuclear warfare. Nagasaki and Nishisonogi Peninsulas are located within the city limits. The city is surrounded by the cities of Isahaya and Saikai, and the towns of Togitsu and Nagayo in Nishisonogi District. Nagasaki lies at the head of a long bay which forms the best natural harbor on the island of Kyushu. The main commercial and residential area of the city lies on a small plain near the end of the bay. Two rivers divided by a mountain spur form the two main valleys in which the city lies. The heavily built-up area of the city is confined by the terrain to less than 4 square miles.