ONSEN review: entrance ¥500 (free for the hotel guests), very friendly staff. The reception where you pay is at the 2nd floor, here you can get your onsen stamp as well. Shampoos provided, you need to bring your own towel, there are lockers and parking. They have two different onsen, at the 1st and 3rd floor. When I visited, during the morning time it was 1st floor male - 3rd floor female and during the night time the opposite, 1st floor female - 3rd floor male. It was night time so I went to the 3rd floor. The tub was large and they try to have some kind of natural setting, stones around the bath, some plants in the middle of the washroom which has 6 places to wash, there are big photos of waterfalls and the water flows in the tub falling from above from two tubes which are covered in bamboo to give the more natural feeling. If you sit under the falling water it can massage your back. The water was not very hot, the attached thermometer wrote around 36 degrees Celsius (average onsen water temperature in Beppu is around 40-42 degrees Celsius) but it gave a nice silky feeling on your skin afterwards. On a weekday night there was just one more person while I was there who left so I had the whole place for myself. Finally there are hair dryers and cotton buds. A nice experience if you don't mind the water not being that hot.