Probably more than you want to know LiD, but here is the full door where the dragon fly was sitting some time ago. What a pity it has been graffittied. There is another wall, so I could not get any further away for a wider picture. Above is a vent of some sort, which leads me to believe it may be a door to an old lavatory. The vent is very high up, far too high for anyone with a paint spray can, so they must have stood on shoulders or had something to stand on. The step is not well worn, almost looks unused.
Not sure why I have posted a picture of such an ugly door really.