They look a little like grain silos.
They might also be some kind of rocket launching platforms.
What are they?
O.K. Here's the answer.They're just supports for a dock at Watson Lake near Prescott. It's the ground level approach of the first photo that may have fooled you.
It was a beautiful day to visit the lake, which is full of water from the rain and snow we've had this winter.
Also enjoying the day were some waterfowl.