Geograph - photograph every grid square

A formal version of community book exchange schemes that have been around for many years, but claimed to be American in origin :- Link Link. Bring a book and swap it for another; borrow one and bring it back. There are now 80000+ in 90+ countries worldwide registered on their website. There will be many more – only three of the five I found in Edinburgh appear on the website’s map, and I know of two others that do not appear. As might be expected, they are not always treated as one would wish. The contents of the Stockbridge one were stolen one night in July 2017 - thanks to the community, they were quickly replaced.