Not every library is in a big building. Some libraries are very small. A Little Free Library can be the size of a birdhouse! Some little libraries are even built in the trunks of old trees.
A Little Free Library lets neighbors trade books. Anyone can start one. Most Little Free Libraries are wooden boxes. The boxes are filled with books. You can take a book. Then you can leave one for someone else. “It’s a great way to share a love of reading,” Margret Aldrich told TIME for Kids. She wrote a book about Little Free Libraries.