Margaret Rose Kane gets sent to camp. It is her first time and the other girls in her cabin decide to make Margaret Rose's life as miserable as they can. Margaret Rose engages in mostly non-violent protest and eventually, with the help of the apparently dim-witted janitor, she gets a ride back to her favorite crazy uncles' place. The uncles have built over the years a kind of art tower, and when Margaret finds out that her uncles have tried to keep from her the knowledge that the upscale neighbors are trying to take it down, Margaret hatches a desperate plan to save the towers and rescue her summer.
Pretty much every character in this book is someone worth getting to know. The book deals with a host of interesting themes, from how you respond when everybody seems to be against you, to recognizing that people are not always shat they seem, to the question of whether beauty is more important than progress, to the value of a place, to lots of other things worth thinking of. This would be a good read-aloud for sixth grade and up. there is the occasionally marginally vulgar word, but nothing that could result in a serious challenge.
This is a book that you will want your students to know about (and one many of them will come to love).