Stink Pipe

Until we moved to Norwich last winter neither of us had heard of stink pipes, or stink poles, but they are quite numerous in these parts (common in parts of London as well apparently).
They’re basically a tall vent from the main public sewer beneath, built high enough to keep any smells well away from the noses of passers-by.
I’m not sure how the main sewers in other areas vent their noxious gases!