"Niels Holgersson's Wonderbare Reis" by Selma Lagerlöf and Margaretha Meijboom is a children's book written in 1906. Young Nils Holgersson delights in tormenting farm animals until an angry kabouter shrinks him to thumb-size. When wild geese fly overhead, Nils unexpectedly joins them on their journey north to Lapland. Traveling across Sweden on the back of a goose, the tiny boy faces danger, adventure, and life lessons that transform him in unexpected ways. (This is an automatically generated summary.)
These books are free to read. Each is in the public domain in the United States; check your own country's rules before you copy or share one.