I absolutely love this. Reminds me of an adobe bubble house I saw in an article many years ago. Richard Olsen's Book Handmade Houses Showcases Beautiful and Unusual Homes : Architectural Digest. Probably for my future little house in Europe.
The DutchTub, a "low-tech" jacuzzi that uses a very rudimentary heat exchanger coil to heat the water. This idea can be used for heating water via open flame, adjoining grills or stoves, coiling etc. - Me: human salsa bowl!