Holes by Louis Sachar

Stanley Yelnuts is a very unfortunate boy. One day while he was passing under a bridge, a person who had stole a pair of expensive shoes, throws the shoes from the bridge, and they land in Stanley's backpack. He is caught by the police and is falsely accused of having stole them. He is then sent to Camp Green Lake, where he is forced to dig one whole each in the desert. One day, zero one of his new friends, of Camp Green Lake decides to escape. Later Stanley finds out that Warden, the director of that place is making children dig wholes to find a treasure. Stanley decides to escape and finds zero. Stanley and Zero find a place called the Thumb of God, where there is food, water and shade. They manage to survive and go to the police, and Warden gets arrested.