20.07.2015 22:11

梅雨 (rain season) is practically over. That's great news, since it means it is possible again to go out without carrying around full rain gear. However, what follows is not a summer in the European sense of the word. Instead of long, warm days inviting people to get out of their houses, for the next 3 months or so, it will be so crazy hot and humid outside that any bodily activity close to sea level is not fun at all. It's still technically possible to go cycling, but that includes drinking more than one liter of energy drinks per hour, funked up with some extra salt, and the clothes building up a white, salty crust over time due to the body's desperate attempts to somehow regulate the core temperature, even though the surrounding air is somehwere around 38°C. It's really not fun.

That leaves only two options for avoiding the heat while still being outside - dipping into the ocean, or escape to higher altitudes. The latter is the more exciting option, so I went for that. Luckily, Japan land mass is covered by mountains for about 80% of the area, so there's not really a shortage of mountains here. And since 登山 (mountaineering) is hugely popular in Japan, it's also relatively straight-forward to go there, even from Tokyo. On the weekends, there are dedicated trains, the ホリデー快速 (holiday express). They are packed with people of all ages in mountaineering outfits, leave Tokyo between 4 and 6 in the morning, and go to various popular hubs in the mountains, from where people are further distributed with local bus lines.

That system allowed me to be at 丹波山村 (Tabayama-mura) at 9:30 in the morning, for a full 9 hours or so of daylight left. In a country with a timezone picked as poorly as Japan's, that's quite a lot.

丹波山村 is more than 600m above sea level, already giving some significant relief from the sultry air in Tokyo, and heading into the woods from the trail head, it got even better due to a small river, and shade from the trees for most of the way:

Gaining elevation quickly, a bit more than an hour later, I was already at 1288m elevation, which is pretty much a perfect elevation for a Japanese summer day. It also happened to be the peak of this particular mountain, 鹿倉山 (Shikakura-yama). The great climate had to suffice though, other than that, the peak doesn't provide any views whatsoever, and only a meagre sign marking the spot is to be found:

From there, the trail basically follows the ridge of this particular range, and crosses over to 大寺山 (Ootera-san), while always hovering above 1000m, and mostly in the shade. Thankfully though, the tree cover opens up in between at least for a bit, for a quite nice panorama over 奥多摩湖 (Okutama-ko):

大寺山, as the name suggests, indeed has a giant structure with Buddha figures on top, which is quite a change of scenery after a couple of hours in the forests:

Seizing the opportunity to sit down on the stairs and cook up some lunch, I noticed that the insects roaming around there are of unusual proportions. There was some rather big ants, but more impressively, some big flying yellowish-blackish insect that looked a lot like a super-sized wasp. I wisely decided not to get in a fight with it, and only today found out that this was a 大スズメバチ (Japanese Giant Hornet), the animal responsible for the most deaths per year in the country. That's kind of important information when leaving the relative sterile confines of the urban areas.

Interestingly, that very insect also makes it impossible for local bee keepers to maintain European honey bees, since a handful of those hornets will quickly take out an entire hive. On the other hand, the Japanese honey bees have found an amazingly sophisticated counter-measure to prevent being wiped out by the hornets, which Wikipedia describes thusly:

When a hornet approaches the hive to release pheromones, the bee workers will retreat back to the hive, leaving an opening to allow the hornet scout to enter. At a given point, the bees emerge from their hiding places in an angry cloud formation containing some 500 individuals. They form a tight ball around the hornet that acts like a convection oven: the bees vibrate their wings, generating heat via muscular exertion, and then direct the air warmed around them into the inside of the ball. This causes the interior temperature of the ball to rise to 47°C. While significant, this high temperature alone is not sufficient to kill the hornet trapped in the bee ball. However the bees' activity also increases carbon dioxide concentration inside the ball. The hornet's ability to withstand heat decreases as carbon dioxide concentrations increase. So the 47°C temperature becomes lethal to the hornets. Meanwhile, the honey bees can withstand temperatures of 48–50°C under the same conditions, so the hornet is killed and the bees survive.

Not knowing anything about the advanced warfare tactics employed by Japanese insects, I just kept following the route, which turned out to leave the most interesting part for the last couple of kilometers, where the trail winds across a rather tight ridge line, only to descend at a pretty intense grade:

Once back at 奥多摩湖 (Okutama-ko), which is only something like 500m above sea level, the bus and train can be used to get back into town, luckily already past the craziest heat of the noon.

All in all, that was a highly effective way of avoiding the heat, while being able to reach remote areas that are not accessible by bicycle. I'm sure that wasn't the last excursion on foot for me during this summer.