Nakajima Aircraft Musashino Dispersal Factory Site (Musashino-no-Mori Park)

The area now occupied by Musashino-no-Mori Park in western Tokyo lay on the northern edge of the Army's Chofu Airfield during the final years of World War II, a few kilometres from the Nakajima Aircraft Company's Musashino Plant. The Nakajima plant, established in 1938 in nearby Musashino and merged into the Musashi Plant (武蔵製作所) in 1943, was one of Imperial Japan's largest aircraft engine factories, producing a large share of the nation's military aircraft engines, including powerplants for the Ki-43 Hayabusa and Ki-84 Hayate fighters.

Beginning in November 1944, the United States Army Air Forces launched a sustained bombing campaign against the Musashino Plant, which was selected as the very first target for B-29 Superfortress raids launched from the Mariana Islands. Over nine major raids between November 1944 and April 1945, the factory suffered devastating damage. In response, Nakajima dispersed production to other sites, such as the Asakawa plant in the Tama region.

Concrete aircraft revetments (掩体壕, entaigō) were constructed in the fields surrounding Chofu Airfield to shelter from air attack the Army fighters based there — the 244th Sentai, equipped with Type 3 fighters, flew from Chofu in defence of the capital. These U-shaped concrete shelters, designed to protect individual fighter planes, were built by mobilized workers including students and local civilians. Two of these revetments — known as Ōsawa No. 1 and Ōsawa No. 2 — survive within and adjacent to Musashino-no-Mori Park, serving as some of the best-preserved examples of wartime aircraft dispersal infrastructure in the Tokyo metropolitan area.

After the war, the area was used for various purposes before being developed into Musashino-no-Mori Park, which opened on April 1, 2000. The park spans 385,750 square meters across Fuchu, Chofu, and Mitaka cities, divided into northern and southern sections by the still-active Chofu Airfield. The surviving revetments have been preserved as historical monuments, offering visitors a direct physical connection to the wartime effort to protect aircraft from air attack in the final months of the war.

The site's significance lies in illustrating how aircraft were dispersed and sheltered under relentless American strategic bombing. Together with the nearby Chofu Airfield and the former Musashino Plant site (now Musashino Central Park), this area forms an interconnected landscape of wartime aviation heritage in western Tokyo.