Sounds like a good candidate for a tank farm. Question: Are the cylinders tall and slender like a SILO (farm silo?) or are they squat and big like a stack of poker chips...maybe with a long staircase running up one side? Believe it or not, tall and tanker trucks all the time might be MILK or some farm product! My kin has a huge dairy farm in Bealton (well, just converted to beef) and when I spent time there as a kid, they used to tell me about those.
No, shorter rather than tall. They are not farm-like silos. I've never really looked for or noticed stairs but I'd say their more like a stack of coasters than a Pringles can.
Anyway, I've wondered several times what they were. Best wishes.