What is "superloo"

Usage examples of "superloo".

I can remember, at the time Mrs Parsons was attacked I was hanging out near the Superloo in Euston Station with three girls down from Manchester I found singing and dancing a bit.

Manchester , an activity which led to an unseemly bout of folk-dancing outside the Superloo in Euston Station, and probably a horrible reaction of shivering and thirst, plus a certain loss of memory.