Encased wooden Japanese hot tub...for outside the perfect tiny home. Would be great in a HOT environment but you'd need a pump or chemicals for circulation against bacteria....hmmm, something to think about.
Iya-onsen, Tokushima-ken (粗谷温泉 徳島) Arrived here by riding 233 kms over mountains, through valleys and killer head-winds with several triathlon friends. . .beacoup beer, laughs and great local mountain ciusine