For much of the 20th century, the Town Hall was left blackened by soot and smoke from the industrial city surrounding it. In spring 1972 the building was given its first official clean-up – on previous occasions it had been hosed down by the fire brigade – which revealed much of the detailed stonework. This was strongly opposed by the Leeds Civic Trust, which preferred that its blackness "should stand as a symbol of the city's industrial past and as a reminder to future generations of the air pollution which the city is so successfully combatting".