T The numbers of visitors to children’s library at the national library of indonesia in central jakarta has been declining, due to its conventional interior design. this research proposed an alternative spatial design based on the concept of “national fantasy,” inspired by the lutung kasarung legend, incorporating natural elements to create engaging learning environment.the design solution is manifested through a reading and interactive zone modelled after the form of amanita javanica mushroom, featuring calming pastel color palette and integrated storytelling elements. the design process involved field surveys, literature reviews, and interviews.this research employed qualitative descriptive method, including a literature review on children’s color phychology, field observations on user behavior, a functional needs analysis, and spatial narrative design approach. the results indicate that the implementation of this concept visualizes a child-friendly interior design that fosters culture-based literacy exploration. the design alignes with sustainable development goals (sdgs) number 4 and 9 and is planned to be published in a scientific journal.