I loved this, I Guess they are tubes that are used for pipes or something like that, I love the idea especially for small businesses of spiritual retreats or for small camps, apart from saving money on construction and becoming a striking idea, it is very practical because they could simply move with a crane from side to side and also in the case of children's camps for example, each one would have their privacy and space which would provide more security to the parents.
That's also what I thought, that they are tubes used as pipes, and yes, you are correct, it is very practical because they can be moved by sinply using a crane.