Thneedville was designed as a utopia town by the Once-ler to further adertise his product after which the place is named (the Thneed), but just as soon as his model was becoming a reality, the last Tuffula tree fell and the Thneed factory closed down. Over time, O'Hare took over the town as mayor, being seen as a hero for selling oxygen (though he had to tighten the security to keep the citizens from finding out they can get fresh air for free just by planting a tree). Everyone (except Audrey and, for her sake, Ted) sees the place as perfect, even though everything, including the "plants", has been manufactured in a factory and bought in a store... they even let some kids swim in the over-clorinated "pond" to the point where one or two of them glow in the dark, proving the locals overlook