How can we design great cities from scratch if we cannot agree on what makes them great? None of the cities where people most want to live such as London, New York, Paris and Hong Kong comes near to being at the top of surveys asking which are best to live in. The top three in the most recent Economist Intelligence Units livability ranking, for example, were Melbourne, Vancouver and Vienna. They are all perfectly pleasant, but great? The first question to tackle is the difference between livability and greatness. Perhaps we cannot aspire to make a great city, but if we attempt to make a livable one, can it in time become great? There are some fundamental elements that you need. The first is public space. Whether it is Viennas Ringstrasse and Prater park, or the beaches of Melbourne and Vancouver, these are places that allow the city to pause and the citizens to mingle and to breathe, regardless of class or wealth. Good cities also seem to be close to nature, and all three have easy access to varied, wonderful landscapes and topographies. A second crucial factor, says Ricky Burdett, a professor of urban studies at the London School of Economics, is a good transport system. Affordable public transport is the one thing which cuts across all successful cities, he says.