We haven’t been able to figure out just where this is. A botanical garden, somewhere in the UK. Mom would be about 13 or so. This is a pre-war colour positive image on plastic (celluloid?). I had long thought this was actually a glass slide. However, in the same batch of images, slides, negatives, etc. in which I finally located this image, I found another taken on the same day and realized that the photo is actually just sandwiched between pieces of glass. My grandfather experimented with colour briefly before the war. I think he’d be fascinated by the modern technology in photography.
I had originally thought this was in Lincoln which has a botanical garden with a nearly identical fountain, seen in the background. That has been ruled out.