I saw several of these on my trip a couple of weeks ago. Nothing quite like them here in the States, although there are places called "community gardens".
Your photos are showing me parts of your world that I never knew existed. Keep them coming.
"Allotments" I was going to ask if what I was thinking was correct but I see Revrunner verified it for me. The little garden shack looks just like the place where I would hang out for the better part of the day. Sit there reading my book, having a cup of tea and watch my garden grow.
It all looks very tranquil. Definitely a nice place to spend a Sunday afternoon.
"Schrebergärten" in Germany, used to see these little curiosities all the time when I lived there for a couple of years, never really understood them - nice, though!
It looks delightfully rural and timeless.