I quoted 110.11 because there is no cover on the GFCI.. Considering the greenery in the picture, I'd bet the GFCI face is exposed to water at least every other day via the sprinkers & the GFCI itself isn't identified for the wet enviroment

I'll go with you on 110.26(F)(2).. I was thinking of the sprinkers as "leakage from piping systems" [Linked Image] (I tried!) & the fact that without the cover it's not a "suitable enclosure"

As far as 300.6(B), I'd be hard pressed to place an aluminum box in contact with the earth.. I can see moisture in the soil deteriorating it double time & eating it away... JMO, I always use PVC for anything in the ground when I can..

406.8(B)(1)... Thats where that is! [Linked Image] [Linked Image] [Linked Image]

-Randy