Kawayu hot spring inside a river

Kawayu hot spring inside a river

kawayu hot spring inside a river

kawayu hot spring inside a river

When did you last dig a hole in a riverbed to create a hot bath?

Letting cold river water flow in to find your ultimate temperature?


This article shows you;

  • why ‘Kawayu hot spring inside a river’ should be part of your Japan trip

  • how to enjoy this unique onsen and combine it with the Kumano region

  • where to park you rental camping car and sleep comfortably

You didn’t yet realise that a camper is the best way to explore Japan independently? Find out in  How to.. overnight with a camper in Japan



Kawayu hot spring inside a river

It is tempting to create a hot list of Japanese hot springs. In fact there are many already. You could base your list on beautifying effects of the water, how dramatic a location is, incredible views from the bath and much more. ‘Kawayu hot spring inside a river’ sure features high on my list. There is nothing at first glance, just an ordinary, pebbly riverbank. But look again! Hot steamy water bubbles up!


Beautiful valley, unassuming village

Driving up towards the Kawayu takes you from the rocky coast of Wakayama into the mountains. A curving and mostly new road follows a winding and very wide river valley with blue, glacier-like water. Forest covers the slopes, it is steep and quiet. After the openness of the main valley, turning into the Kawayu-valley feels like entering a gorge. Expectations were high already, especially in the back seats, and the fast flowing river adds to that. Only two more kilometers! I cannot help to feel disappointed when we drive into Kawayu village. Drive along the village is a better description. It is nothing more than a rather short row of houses and hotels, squeezed between the river and the mountainside. At the end, the road quietly disappears into a dark tunnel, as if admitting it does not live up to its expectations. But don’t be fooled!


Find the bubbles

kawayu park on the bank

park on the flat Kawayu river bank

It is all narrow without places to stop so when we saw a car actually parked right on the flat, wide, pebbly bank I thought “imagine camping there, right next to my own pool of bubbly hot water!” Immediately dismissing the idea because riverbeds are danger zones. Water may unexpectedly rise in the night because of a downpour upriver or the scheduled opening of a dam. And there you go, on your way towards the ocean! But parking there for a first touch of hot water was fun! Only, we did not find any hot bubbly water, just a beautiful river filled with cold water rushing by.

Back on the road we found a great parking spot (more practical information below and in the Ride Summary at the end). While admiring the river we saw a couple of ‘yukata-clad men’ head to the water’s edge. In our bathing suits we followed quickly, finally discovering a few small pools, dug into the pebbly bank. And was it hot! Steam and bubbles surfaced when we joined the 4 Japanese tourists in the bath. Soon more of their friends joined and it became quite an interesting afternoon.


Best hot spring with kids

Thing with hot springs and kids is that they have to behave when inside. Play quietly, no running, no splashing. Which is easy, for a little while. Not in Kawayu. This is hands down the best hot spring with kids! They can dig a little boiling hole of their own, move rocks around to adjust the flow of river water into their bath, and the opportunity to throw pebbles is endless. Hours can be spend while parents relax in the water. Together, there are no different sections for men and women in this river. Paradise found!


In winter it gets even better

In the cold and snowy months, the rather quiet ‘Kawayu hot spring in a river’ is bulldozed into ‘Kawayu the worlds largest hot spring in a river.’ Instead of digging a hole of your own, the machines create one gigantic hot bath, where 1,000 people can bath together. This is called ‘Senenburo’ which means something like ‘fit 1,000 people in an outdoor pool’ and is obviously the largest of its kind. I have not seen it yet but imagine the experience, so many steaming bodies in the icy winter mountains. The quiet village will feel different too.

The water quality of the springs seemed fine to me, but I judge by smell and clearness mostly. And many hot springs leave that silky feeling on your skin, but this one did not. Maybe because of the mixing with ordinary river water. Speaking of which, the river makes a great cooling down! Wade in and float slowly downstream. By the time you start feeling the chill you can go right back into a bubbly pool. Regulating the water temperature you do by widening or closing the small channel feeding into your bath; like opening the cold tap, only slower 😉


What to bring: a shovel

enjoy Kawayu onsen

Yukata off and go!

‘Nothing’ is what you usually bring to an onsen. That works here too but 99% of the visitors wear bathing suits. It is fun to watch the hotel guests clamber into the riverbed wearing their uniform ‘yukata’, the simple, cotton variety of a kimono, more like a bathrobe. Soap and such of course are not done. Neither is scrubbing before entering, but with the river as the endless flowing supplier of fresh water that is fine too. Walking barefoot across the pebbles is near torture to me, best to keep your slippers on when skipping between baths. It is also recommended to bring a small shovel! Yes, for easier digging of course. By hand works fine and is a nice little chore but very disturbingly, we found a fragment of a beer bottle while digging by hand. Also a sharp piece of metal, which seemed to be part of a barbecue grill once. Walking around is fine, but especially kids dig in furiously so bring that small shovel.


Practicalities: where to sleep

As the valley is so narrow, there is no abundance of spots to park and stay. There is a makeshift little parking lot just before the first houses which is flat and fine. On the river, stroll to the where the hot water bubbles in around 2 minutes. There are no toilets or anything though. And beware of monkeys, there is a resident troupe. They mind their own business but it is better not to test them. A couple of hundred meters before the village is a campsite. It was abandoned though and looked old. No open facilities there either but you could just park on the river and have a great stay. We did something else.


Onsen tunnel

Remember the tunnel I mentioned earlier? It is called the ‘Onsen Tunnel’ as on the other side is ‘Watase onsen’ which is quiet and known for its large selection of  ‘rotemburo.’. A rotemburo is a hot spring in the open air, so for size Kawayu in winter easily beats Watarase but it has a nice collections of 5 outdoor baths. We went and parked on their parking to cook dinner and next enjoy the outdoor baths under the stars. There is actually a simple restaurant too, that serves all kind of regional fare like ‘noodles in mountain vegetables’ but also ‘Mehari sushi’ (rice ball wrapped in pickled leaves),  Ayu (sweet river fish) and the rare ‘Onsen Gayu’ (hot spring rice gruel). All are Kumano specialties and not always easy to find so take the chance.


Combine your trip

famous kumano onsen

famous kumano onsen

All this goodness is in Wakayama, the southern tip of the large peninsula south of Osaka and Kyoto. Check the Go Camper Japan highlights map for details. There are many sights to see here, you can easily spend a week. Or a long weekend for those living in Osaka or Nagoya. The rocky coast of Shirahama, the holy mountain of Koyasan, the many many hot springs, the pelgrims paths and temples of Kumano. And more. Public transport is available but driving you own car is much more convenient and obviously a camping car is the very best!

Create your unique trip! Go Camper Japan!

Other useful information:

Ride Summary: your details about this trip

Ride Summary Kawayu

** our Members have access to Ride Summaries with even more information. For example GPS locations and phone numbers to make navigation a breeze. And more.

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  4. Michael

    It is not possible anymore to stay overnight on the parking of the Watarase rotemburo… We were told to leave yesterday evening around 21:45 and had to find another sleeping spot by night!
    The little restaurant is still a nice place to go.

    Thanks for the site!


    1. sandor.lrr (Post author)

      Thanks for the update, Michael
      Did you find another recommendable spot or did you use the one we mention, just before Kawayu-village?

      Enjoy your travels, Go Camper Japan!


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