Japan itself is the result if volcanic activity and movement of the plates that together form the crust of the earth. Earthquakes and eruptions have been shaping the Japanese landscape since the beginning of times because of its location on ‘the Pacific Ring of Fire,’ where several plates continuously rub against each other, causing quakes and volcanic eruptions. Go here to learn more. Next to over 1,500 earthquakes per year there are more rewarding side effects of plates moving; hot springs. ‘Lava flows underneath us heat up ground water which bubbles up through the crust, filled with soothing minerals, ready to for us humans to enjoy!’ This is called ‘Onsen’ in Japan and enjoying these is very popular.
In the mountain areas especially many hot springs are found and people have been using them as their source of hot water for ages. Though less popular today, because most people now have heated water at home, you can still find public bath houses all around Japan, even in Tokyo. These had an important social function in the past, where people would gather at the end of the day to wash, scrub, chat, gossip and do business. Just like in Roman times in Europe. In our time it is more about relaxation and the so-called onsen resorts are holiday destinations all year-around and especially a great extra attraction during winter, to relax after a long day skiing.
There is no skiing on the Tokyo Islands but onsen a plenty, some in such spectacular locations that the feature in ‘the Lonely Planet onsen top 10!’ In this post you learn about several of these. Onsen have their specific regulations which you should be aware of when going. Like how to behave and what (not) to wear. Read all about that in our post relaxing-Japanese-style. While most of Japan requires nude bathing and generally genders never mix, on the Tokyo islands for some reason unknown to me, there are many baths where bathing suits are required and all can enjoy the waters at the same time.
Volcanic Oshima consists largely of Mount Mihara and on its flanks you can find several hot springs.
Two highlights are;
・Motomachi Hama-no-yu; a nice place but the best reason to visit are the wide views over the ocean from the baths. It is located just outside Oshima Town, on the west coast, 10 minutes from the port.
・Oshima Onsen resort; this hot spring has open views of Mount Mihara and the volcanic plains. That is, on a clear day. When the clouds come in you will not even know the mountain is there. It feels very remote and quiet to soak in the outdoor pool with clouds all around you. Although part of the resort, day visitors are welcome.
Here we also highlight two hot springs;
・Yuno-hama onsen; a public place and only outside, on the rocks with stunning views of the ocean. Do bring bathing suits. It doesn’t look very traditional Japanese with its greek-columns but hey, it’s free, go (again) at sunset or even at night under the stars! It is situated a 5-minutes walk south from the tourist office.
・Mamashita onsen; another 5 minutes or so on you get to this place which is special for its hot sand-bath. These are very rare in the world and a highlight for many. it is simple; you dig a pit in the hot sand, lie down in it and slowly heat up. A bit scary at first to be buried and stuck but it feels so nice and warm all around. After a while you know what it must feel to be a hatching turtle egg when you dig yourself out again.
A tiny island a stones thrown south of Niijima which makes a great daytrip. If only for the onsen. This is the place the Lonely Planet includes in the Japan onsen top 10.
・Jinata onsen; this is the place not to miss and you might want to go more than once to test the water temperatures. Why? because there is an open connection to the ocean so the tide decides how much hot spring water and how much (cold) sea water is in the bath. Automatically, be aware that at low tide it gets very hot! The other draw is the location, spectacularly ‘stuck in a cleft in the rocks,’ on the oceans edge.
・Matsugashita-Miyabi-yu; this is also a rotemburo (outdoor bath) on the oceans edge but the tides don’t play a role here. Fine views of the ocean are yours, find them near Ashizuki port.
・Urami-ga Taki onsen; a little gem well worth the long boat ride to this island is also a bathsuit only place that is free of charge. Daytime only and it requires a bit of a hike to get to. Image sitting in a hot pool in the forest overlooking a waterfall.
・Miharashi-no-yu; what to say, the picture explains it way better!