I've been up late nights wondering the very same thing.
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The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts. (Bertrand Russell)
sorry, the above is not a gasometer. My mistake comes from the fact its called "Usina do Gasometro", but in reality, its a thermoeletric powerplant (now deactivated) that got its popular name because it was next to a gasometer, which was demolished.
shit, i never knew that. I researched now, after I saw the pictures posted above of other gasometers and noticed that it was something completely different.