Can you help with 'Bolton grammar school baths' photo?

This sepia-tinted photo from the archive is something we need Looking Back readers’ help with. Can you identify the baths? The only information we have is that in pencil on the back of the photo is written ‘Grammar School Swimming Bath’. There’s no date but judging by the quality of the picture it is old, possibly from the 1920s.

And the baths were pretty ornate with changing rooms set into stone archways and a large window at one end. But where was it? Did Bolton Grammar school ever have its own baths? If you can help shed more light on the photo, leave a comment..