This is one of those designs that seems so ridiculously simple, that when someone praises it you know there are at least a couple people grumbling under their breath that they totally could have thought of that themselves. The sad thing is, we never do, the simplest most obvious ideas don’t always come to the general public. Probably because we tend to think surely someone thought of this before. Well this one was designed by Floris Schoonderbeek, you site you can check out here. Floris made a lo-tech hot tub by harnessing fire to heat up the water. This way you can put it out in the middle of nowhere if you want without worries of having power to hook up the tub with.
The down side is that since it is heated by fire it doesn’t stay on all of the time. Which means it’s going to take a little time for the fire to heat the water again, 2.5 hours to be exact. I could imagine that would get frustrating for some. Yet, the perk of having a tub right out in the middle of gorgeous scenery with not a house in sight would definitely be worth it for many.