Cosimo Piovasco di Rondò is a fictional character from the novel "The Baron in the Trees," written by Italian author Italo Calvino. Set in the 18th century, Cosimo is a young nobleman who decides to live in the trees of his family's estate in Italy after a disagreement with his parents. He spends his life in the treetops, developing a unique perspective on the world below. Throughout his life, Cosimo interacts with various characters, including his family, friends, and the local community. His adventures highlight themes of freedom, individuality, and the relationship between humans and nature, making him a symbol of unconventional living and thought.