Sumiyoshi WWII tunnels
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A rather less well-known relic from WWII in Nagasaki: a few preserved sections of tunnels that were originally dug into the mountainside in a northern suburb of the city towards the end of the war to provide sheltered space for the production of torpedoes. More background info: As the war in the Pacific was increasingly turning against Japan, with ever intensifying air raids by US B-29 bombers, it was feared that the Mitsubishi Industries arms manufacturing plants of Nagasaki would be a prime target and so efforts were made to a) decentralize production to limit potential damage and b) move some of the production underground. In late 1944, work began to construct six parallel tunnels in the mountain between Sumiyoshi and Akasako in the north of Nagasaki, about one kilometre from the Ohashi Mitsubishi arms factory.
The tunnels were to be 300 metres long each, 4.5 metres wide and ca. 4 metres high, and arranged in parallel, some ten metres apart from one another. When the first tunnels were ready for use, machines and equipment for the production of parts of torpedoes were moved here. These parts were then taken to the main Ohashi plant for final assembly. By August 1945, all tunnels were in use even though the final one was still being dug.
Crucial in the construction of the tunnels were Korean forced labourers. They were mainly involved in the excavation of the tunnels, which was obviously hard and dangerous work. The approximately 800 to 1000 Korean forced labourers were housed in special “dormitories” nearby.
Production of torpedo parts inside the tunnels was carried out by some 1800 workers, including mainly “mobilized” students.
In the wake of the A-bombing of Nagasaki on 9 August, the tunnels, the insides of which had survived largely intact, became a refuge centre for the injured of the surrounding area, including survivors from the Ohashi arms factory.
After the war the tunnels were abandoned. It was only when the road that now runs above the tunnel entrances was expanded that the site was turned into a memorial. Of the six tunnels four were completely blocked off, only tunnel 1 and 2 are partly visible. The entrance sections were reinforced with additional concrete for safety reasons. The site is under the auspices of the Nagasaki Atomic Bomb Museum.
What there is to see: When I was in Nagasaki in April 2019 I was lucky enough to be shown around by a local historian associated with the Oka Masaharu Memorial Peace Museum, who I had met the day before at the museum. He offered to drive my wife and me to the site, and what's more: he had a key, so we were even able to get inside one of the tunnels. Hence I was able to take photos like Nos. 5 to 9 in the gallery below.
Normally (but see below) you can only look into the tunnels through the metal fence and locked door at the entrance. As you get near a motion detector switches on lights inside the front part of the tunnel so you get a better view. Of the two preserved tunnels only one (I believe it's tunnel No 2) is still open most of its length and you can see the rough raw-rock-hewn main part, while the first stretch by the entrance has been reinforced with concrete for the first ca. 20 metres in order to stabilize it (after all a major road carrying heavy lorries runs overhead these days). You can peek into the dark, but there's no light at the end of this tunnel. The opposite end is blocked off.
The other tunnel is blocked off already after a few yards and its walls are completely covered in concrete. Inside this shorter tunnel an old rusty torpedo is on display, presumably of the sort that were manufactured here (well, parts for them).
There are three large information panels with photos and explanatory texts, in four languages: Japanese, English, Chinese and Korean. The English translations are very good (something that can not at all be taken for granted in Japan). The panels are quite detailed and you learn a lot going through them. Interestingly, the fact that some of the “mobilized workers” were Korean and in fact forced to work here (under harsh conditions) is mentioned, which is also something you don't find very often openly acknowledged in Japan.
So even though this is a comparatively obscure spot and not at all a top sight, it is still worth the little extra effort to make your way out here, perhaps after visiting the Atomic Bomb Museum.
Location: in the north of Nagasaki, in the Sumiyoshimachi district, ca. 1.5 miles (2.5 km) from the Atomic Bomb Museum and ca. 4 miles (6.5 km) from the city centre. The tunnels' entrances and the three info panels are underneath the main road through Sumiyoshimachi.
Google Maps locator: [32.79454, 129.86087]
Access and costs: Quite off the beaten track and potentially a little tricky to find; free.
Details: To get to the tunnels independently you can take tram lines 1, 2 or 3 from Nagasaki station or the city centre and get out at the Sumiyoshi stop. From there walk in the direction the tram continues but turn right at the next intersection. From there it's a ca 250 yards walk. The road becomes a part flyover with a large (private) car park down to the right and a hillside with residential buildings to the left. Just before you come to a convenience store on the right, look out for the steps leading down to the car park level next to the elevated road. It's only when you've taken these stairs that you'll see the tunnel entrances, as they are hidden below the road.
The site is freely accessible at all times, even at night, if you wish. There are motion detectors that automatically switch on lights inside the tunnels when you get to the gate to give visitors a better view of the inside.
Actually accessing the inside of the tunnels is normally not possible, but when I was in Nagasaki in April 2019 I was with a guide who had a key, so I was allowed in, but only as far as the reinforced-concrete-clad section went, not deeper into the raw-rock-hewn part.
Apparently you can also contact the Atomic Bomb Museum, who are in charge of this site, and ask to be allowed in. How well that would work I cannot say, as I didn't have to take that route. But I've read notices to this effect in various online articles about this site, so I guess it must be a real option.
On a few days of the year, however, the tunnels are open to the general public anyway, namely around Nagasaki Peace Day (7-10 August) and for UN Disarmament Week (24-30 October).
Time required: Not long, just a few minutes to view the tunnels and maybe another 10 minutes or so to study the information panels.
Combinations with other dark destinations: See under Nagasaki.
When I went to the tunnels it was as part of a guided tour I did with a local historian who I had met the day before at the Oka Masaharu Memorial Peace Museum and who had offered to take us to some of the lesser known war-related sites in Nagasaki by car. And en route to the tunnels we also made a stop at the memorial for the workers killed by the A-bomb at the Ohashi Mitsubishi arms production factory (see under Nagasaki for location). The plant's gone, but a bit to the north of the memorial there's still a building of the Mitsubishi Industries, namely an aquadynamics testing centre, which we also passed en route.
Combinations with non-dark destinations: The suburb the site is located in doesn't offer anything for tourists really, so better head straight back to Nagasaki proper.
