The Little Free Library Project

The Little Free Library is a nonprofit organization that aims to inspire people and help build community by encouraging people to install book exchanges in their neighborhoods. Since 2009, the organization helped install over 75,000 libraries in 88 countries and exchange millions of books annually, spreading the love for books everywhere. Recently, inspired by this project, one librarian from Idaho decided to create her own unique little library.

It was created by Sharalee Armitage Howard, an artist, librarian and former bookbinder from Coeur d’Alene, Idaho. Her family recently had to chop down a 110-year-old cottonwood tree standing in their yard and decided to not let its trunk go to waste by installing a tiny library inside it. They carved it from the inside and decorated it with a tiny shingled roof to give it a cozy, magical look

I pass these sometimes on my travels in Vancouver so must keep some books in the car so I can contribute something.
https://littlefreelibrary.org/start/

Some other examples. I especially love the British Phone Booth design since I imagine these phone booths like all phone booths will be a dying breed.