Thorn Castle (1967)

Tutajos is a skinny, dreamy boy who is so feared by his parents that they won't even let him go to summer camps. Instead, if he passes his exams well, they let him visit his uncle at the countryside. His uncle is a busy man, so his wife entrusts him to her brother, who lives in a small hut, far from civilization, surrounded by nature. After his initial clumsiness, Tutajos picks up the old man's survival skills and the love of nature, and at the end of the summer he returns to his parents as a grown up adult.