Ten, Farewell from Duct Work Man

Our final whimsy of this trip was just before our finish:

Nine, Simplicity

What is it I like about these humble structures? Their lack of pedigree? Their age? Is it their elegant, spare proportions? Their use of available , natural materials?
Maybe their symmetry?
Or perhaps their easy, yet respectful relationship with their elaborately embellished natural surroundings?
What do you think?