After decades of blight, large swathes of Detroit are being reclaimed by nature. Roughly a third of this 139-square-mile city consists of weed-choked lots and dilapidated buildings. Satellite images show an urban core giving way to an urban prairie.

As the world changes around our cities, and their urban form becomes irrelevant to current social needs and behaviors, perhaps allowing unused and under-used tracts to return to nature is not such a bad idea. This, combined with brownfield infill development, could help us rethink and rebuild our cities, making their forms more relevant to life in this century, and promoting wiser use of land.