The book "Once Upon a Time..." is an engaging children's book that addresses a variety of critical environmental issues. It has been specifically designed for young readers and presents complex topics in an understandable way. Authors Hadar Elyashiv and Gema Martínez Méndez have ensured that the content is both informative and appealing. Numerous illustrations complement the texts and facilitate the understanding of the topics discussed. This book not only raises awareness of environmental issues but also stimulates the imagination and critical thinking of young readers. It is ideal for children and teenagers who want to learn more about the world around them in an entertaining way.