A new Japanese-style onsen is opening next week, with a soft opeing tomorrow. Unlike the still relatively new Yunomori Onsen on Sathorn Soi 10, this one is only for guys. On the other hand, unlike Yunomori which opens at 10:00 am and closes around midnight, Kaikan Onsen will be open from mid-afternoons till the early morning hours. Whether that means there will be any action I do not yet know. I have also been told the owner operates at least one gay sauna. So it may be worth a visit. Location is near Saphan Kwai but please note it is closed on Wednesdays and Thursdays.

I have read somewhere that there will be a limit of 50 patrons at any one time. Hence the sugestion on the website that reservations are made in advance. Entrance is 450 baht making it 100 baht cheaper than Yunomori - unless you are 65 and over in which case Yunomori has a special rate of 300 baht. The Yunomori seems considerably larger. Although the photos on the website below feature ladies, the men only section is large, has around 18 showers, 7 pools, sauna, steam room and around 300 lockers. The Japanese-style cafe is available to both sexes for which yukata are provided and the food is excellent.

https://www.kaikanonsen.com

On the map, Saphan Kwai Skytrain station is on the upper left and the onsen is on the bottom right.

https://www.yunomorionsen.com/sathorn/onsen/

Just saw one pornstar did a visit/tour ig stories of the place. Looks like a great place to wind down!