The mistake people make in trying to create the perfect city is to make it too perfect. The design of anything from first principles often neglects the reality that truly great cities emerge out of chaos.
To plan out a perfect city you must first acknowledge the futility of planning. What I hope would emerge from the chaotic development of the city is variety. People speak of the culture of a city, but the great ones are an ecosystem of cultures existing in equilibrium. As they combine and interact, new intersections emerge meaning that the city is in a perpetual stage of growth. Rather than homogenous stagnation, exacerbated by starvation of cultural oxygen, which breeds only suspicion and mistrust of that which is different, the perfect city is eclectic.
I want this city to have sunny places, dappled by the shade of trees which give us a different perspective on time. These trees remind us, as we dart around the city living out our busy lives, that they were here before us and will still be here long after us. The city should have wild places. But it is here, that the first mistake of the planner can emerge. In our attempt to fit nature into the city, and design for the wild, we make plants our prisoners and force them to stand grotesquely in positions that match human aesthetics. Instead, nature should also be given the chance to go crazy. Wild variations of plants appear haphazardly, an apple tree grows on a corner but as a result of the wild mixing of DNA the apples are inedible to most. And yet still it remains, there, without question as to its utility. That's what tells us the system works.
There should be places we can work in and help us to connect and collaborate, but this should not be done at the expense of spaces that remind us why it is all worth it. When a resident of the city is asked where one can dance, their reply should be an endless array of names. When they list a place that they have a particular memory associated with, we should be able to glimpse the momentary smile of nostalgia for a split second while the word is leaving their mouth as for a moment they are there once again. The city should be integrated. People should mix not because they are forced to but because the rich culture where people eat, drink and dance attracts people from all walks of life. When they sit at the tables and eat the food they do so because all are able to appreciate the effort of the artisan and the quality of the fare. Its merit is conveyed by its own quiet reputation without needing the backing of a cultural establishment or celebrity endorsement.
Finally, the city will be flawed. There will be cracks that haven't been repaired, and buildings that are home more to nature than to any resident. There will be things missing, systems to complain about and problems to rally together to solve. Without this, there is no moving forward. People join with a common purpose to tackle problems that affect everyone and the city grows stronger and more resilient.
Some people will see these flaws and move on. That is okay, there are cities aplenty for them. Should they not find them in their wanderings, they remain most welcome to return again. They will find me sitting on the crooked bench under the shade of the apple tree whose fruit is much too sour.