The 1,249 acres of Naval Air Facility Atsugi lies in the heart of the Kanto Plain on Honshu, the main island of Japan. The base was originally built in 1938 by the Japanese Imperial Navy as Emperor Hirohito’s Naval Air Base. There were other air bases in Yokosuka, Kisarazu and Tateyama; however, these were regarded as being unfit bases for the larger planes to be used by the Japanese Navy in the future. The surrounding area was almost evenly divided into two parts — mainly farmland and forest. Most of the latter consisted of pine trees and underbrush. For transportation facilities, there was the main line of the Odakyu Electric Railroad, Fujisawa Line and the Jinchu Line.