Confused about where the “Pouch of Douglas” is ?

Had surgery on New Years Eve, they removed two patches on my left pelvic wall and then a patch from my “Pouch of Douglas” which I can’t work out fully where it is, and the nurse there when I was being discharged also didn’t know. I’m pretty sure it’s gotta be somewhere in the pelvic region. I’ve tried looking up diagrams but that’s also confused me more 😅

Other than this confusion healing from surgery has been going well aha