Lud's Holm main hatch - Sally Act 2

[Samshine]

I have been searching for hours through every street trying to find the underground station for Lud's Holm in Act 2, and can't find it anywhere. I have uncovered all of the map, I've found both of the other two hatches (Luds Holm 2 and Eel Pie Hatch 2) and every other hatch in my list is uncovered.

 

Any suggestions? I can only assume it is meant to be on the main island somewhere but having scoured every street and all areas inbetween the streets I am at a loss.

 

Any help would be appreciated. Thanks.