Morinomiya (Former Osaka Army Arsenal) about 60 years ago and today

History of Morinomiya (Former Osaka Army Arsenal)

East of Osaka Castle there is a corner whose color changes drastically with the era of the aerial photograph. In the photograph from around 1936-42 it is black as if ink had been laid on it, in the 1945-50 photograph it turns into a gray roughness, and in 1961-69 white park paths run winding through it. The site of the Osaka Army Arsenal, the army's weapons factory placed east of the castle, was covered in black. The castle site was taken over by the Meiji government, and the fact that the flat land continuing east of it was vacant in one piece was the reason it was chosen as the place for a large factory. The place name Morinomiya is said to come from the shrine of Mori no Miya in this area. The land after the factory disappeared was divided into three: a park, tracks and town.

The oldest era in which the factory appears is around 1928; the gray grain is large, and individual houses are crushed together. Even so, the moat and woods of Osaka Castle on the left of the frame can be recognized at once as two dark masses, and to their east long, narrow rectangular buildings line up facing the same direction. Many of the buildings carry several thin ridgelines on their roofs, and a corner with diagonal stripes is mixed in. East of the group of buildings a bright, blank surface is taken widely; its edge is not straight but a gentle curve, and dark, mottled woods are scattered inside it. Outside the site, in the northwest corner a river meanders with a band of tracks alongside, and the east side changes into a grid of fields and rows of houses. The lower half of the frame is a fine, dense city area, with roofs packed right up to the outside of the factory.

A surface hidden with ink

Around 1936-42, those groups of buildings disappear from the photograph. There are two black surfaces. One is a large, irregular surface spreading from the east of the castle to the north; its northern end touches the river, and its southern edge is cut almost straight along a road. The other is a surface close to a rectangle southwest of the castle, with thin horizontal lines lined up inside. On both, countless diagonal lines that look like brush strokes run over the top, and white dots left unpainted are scattered inside. Meanwhile, in the same photograph, the double moat of Osaka Castle and the white buildings lined up neatly inside the castle are clearly visible. It is not that the photograph is bad. This is a surface that was hidden after it was photographed. The dense city area lies south of the black surface, with white rectangular buildings gathered in it, and a bright band that looks like a river comes in somewhat inside the right edge, with a bridge across it.

The gray of the burned ruins

The black surfaces disappear in 1945-50. The same area returns to clear tones of white and black, and a large rectangle with white stripes appears toward the top of the frame. These are buildings whose roof ridgelines still remain. To their west and south dark rectangles line up in stripes, looking as if they have lost their roofs and become only frames. From the center downward a gray roughness spreads irregularly, with almost no outlines of buildings. Only a few curved paths pass through. In the air raid of August 1945, this factory suffered heavy damage. Right of the middle, the dark band of a river runs north to south, and at the very bottom a thick white straight road crosses east to west. Rows of houses remain in the city area to the west, but they are broken in places by dark patches.

Park paths and a black mass

The park paths appear in 1961-69. The left half becomes a wide, bright grayish-white surface, where winding curved paths cross and dots of trees are scattered. There is one bright oval surface in the upper left and long, narrow rectangular lots lined up in the lower left, and at the junctions of the paths there are round plazas. By this era the western half of the burned ruins had been remade as a park. On the other hand, in the center of the frame bundles of north-south tracks line up in several lines and curve to the northeast at the northern end. East of the tracks there is a huge pitch-black rectangle, with thin horizontal stripes densely lined up inside. It is in almost the same position as the buildings that appeared with white stripes in 1945-50, and it is long from north to south. A bright open space lies to its south, with long, narrow buildings with thin stripes left here and there. Toward the right of the frame the river meanders north to south. Toward the bottom of the frame there is one round building, and it continues to appear in the same place in later eras.

Of the three color photographs, the oldest, 1974-78, takes on color differently surface by surface. The lower half leans strongly toward ocher, and the upper half sinks from blue-green into darkness. The dividing line is a zigzag. The castle moat is a dark water surface and the main enclosure is a brown surface, with a white dot that looks like the main keep on it. East of the castle, radial and ring-shaped paths form a clear mesh, with two or more round plazas. Toward the north a wide, sand-colored oval surface has been made, with the outline of a circle faintly visible inside. To its northwest, long, narrow dark buildings are still lined up in stripes. East of the bundle of tracks there are two large dark roofs with thin stripes densely lined up, north and south of each other, and farther east a large surface with a grid pattern and roofs that look like warehouses continue. In 1979-83 the bias in color disappears, and the boundaries between surfaces can no longer be seen. The mesh of park paths and the sand-colored oval are still there, a thick band runs off from the north to the east, and another thick straight band crosses the middle of the frame east to west.

The great oval roof

It is in 1984-86 that a great oval roof shining black appears toward the north of the park. It is the only thing of conspicuous size among the woods of the park, and its position almost overlaps the place where long, narrow buildings were lined up in stripes in 1974-78 and 1979-83. The groups of buildings were cleared away together, and a single large roof was placed in their wake. In 1983, Osaka-jo Hall opened toward the north of Osaka Castle Park. A bright, sand-colored oval surface spreads just southeast of the roof, its edge enclosed like an embankment, with a faint fan-shaped shadow falling inside. The surrounding woods are denser than in the previous era. The bundle of tracks is still north to south, and east of it dark roofs with thin stripes, a large surface with a grid pattern, groups of white rectangular buildings and wine-red roofs are mixed together.

The past photographs stop at 1984-86, and the next one is today's. Forty years of change appear all at once. The oval roof has changed to a bright blue-green, with concentric outlines standing out inside. The sand-colored surface to its southeast has rounded into a circle, with a dark green round clump sitting at its center. The paths of the park are still a mesh of curves; from the round plaza toward the south many lines radiate, and toward the southeast a wide stepped path descends. The bundle of tracks keeps its width north to south, and large roofs still sit in the area where the dark roofs with thin stripes continued in 1984-86. You cannot tell from the photographs alone whether they are the same buildings. To the northeast, long white roofs covered with a fine grid line up, and east of the tracks many white high-rise buildings stand. A group of high-rises can also be seen at the northern edge of the frame. Just inside the right edge a thin, dark waterway meanders from north to south, and a road raised on pillars crosses the middle of the frame east to west.

The height of the land in this area differs clearly by direction. The measuring point to the west is 11.1 m, and the east is 0.9 m. The difference exceeds 10 m. The center is 4 m, the north 4.9 m and the south 3.1 m, so the location is placed partway along a slope descending from west to east. The rise on which the main keep sits is on the west side. It is the job of the City of Osaka's official hazard map to show how the difference in height shows up in the actual movement of water.

The observation point for official land prices (Chika Koji) is in a residential area of Morinomiya-chuo 1-chome, 304 m from this location. 480,000 yen per square meter is the value for 1983, and from there it rose to 1,580,000 yen in 1991. In the record from 1983 to the 2026 publication, the highest is this 1991 value. After that the decline continued, and the lowest years up to the 2026 publication are 2011 and 2012, both 475,000 yen. That is 5,000 yen lower than the starting year, 1983. In 2026 it is 715,000 yen, 240,000 yen or about 50% higher than in 2011 and 2012. The middle of the 1980s, when the great oval roof appeared, falls partway along the climb from 480,000 yen toward 1,580,000 yen.