It is a take one and leave one setup so they can’t be stolen and the same books aren’t expected to be out there for long periods of time.
Perhaps the most well-known is the extensive beach library at Albena, a restort on Bulgaria’s Black Sea. Designed by German architect Herman Kompernas, it’s built to withstand the sun, water, and wind, and equipped with a vinyl cover to protect the books in rain. It reopened this May with more than 6,000 volumes in 15 languages, all totally free to take — and visitors are encouraged to leave their own tomes for others.
Not only that, they will be full of sand within a week, if they are not stolen
It is a take one and leave one setup so they can’t be stolen and the same books aren’t expected to be out there for long periods of time.
https://www.atlasobscura.com/articles/libraries-on-the-beach