Over the last 20 years, slums have experienced something of a revival in the popular imagination. A series of UN-Habitat reports on the issue of slums, media images of sprawling and heaving settlements, and a host of scholarly interventions — notably Mike Davis' work Planet of Slums — all have served to sharpen attention on the size and growth of slums across the globe. While the word "slum" may conjure a Dickensian world, it is now proving historically malleable, making us look not only backwards, but forwards. For Mike Davis, the future holds a "Planet of Slums"; for UN Habitat, it holds "Cities without Slums." Either way, the image of the slum has become integral to how we visualise the future of our urban spaces — and as slums increasingly shape projections of the future, two contrasting and forceful images have emerged. How has the slum come to define both an urban utopia and a crisis of modernity? Read more.