Oppenheimer led a committee which came up with a list of cities most potentially suitable as targets of atomic attacks. The committee eventually arrived at the recommendation of four targets: Kyoto, Hiroshima, Yokohama, and Kokura.
Hiroshima was chosen as the first target due to its military and industrial values. As a military target, Hiroshima was a major army base that housed the headquarters of the Japanese 5th Division and the 2nd Army Headquarters. It was also an important port in southern Japan and a communications center. The mountains surrounding Hiroshima also contributed to Hiroshima being among one of the top choices among the short list of potential targets, for that the mountains might contain the destructive forces of an atomic blast in the target area, increasing the level of destruction (Chen).