Aalsmeer Flower Auction
What better way to fill such a large space? The auction building of a flower auction in Aalsmeer, the Netherlands, is the largest building in the world by footprint, covering 243 acres. It is one of the world's premiere flower and plant markets, trading as many as 20 million flowers on a daily basis.
Though a subjective measurement, it's probably safe to say that this building is also the most fragrant large building in the world.