Bavel's Book

Overview

A boy and his young sister were curious about the book someone had left on a bench, and they opened the book. Then the small Tower of Bavel was completed on a page. Looking into the tower, they found an old man sitting and reading a book, surrounded by innumerable books. As the man turned pages, mythical animals appeared and disappeared. (Source: yamamura-animation.jp)

Source: AniList