After the US and France, the Netherlands is the world's largest food exporter, but the latest proposal to maintain agricultural production levels by building four six-storey "agroparks" has led to accusations that Dutch agriculture minister Laurens-Jan Brinkhorst has gone mad. Behind the proposal is the Green Space and Agrocluster Innovation Network (GSAIN), who say that each high-rise farm will house enough chicken coops, pig pens, salmon tanks, mushroom beds and greenhouse space to feed an entire city.