%0 Journal Article %T Special Issue: Challenges in City Design: Realize the Value of Cities %A Kongjian Yu %J Challenges %D 2011 %I MDPI AG %R 10.3390/challe2020043 %X In 1900, only about 13% of the worldĄŻs population lived in cities; now the figure has increased to over 50%, and is expected to reach 60% by populations in cities and suburban areas, developing countries are still in the process of urbanization. Every day, hundreds and thousands of people move to the city. Why do we choose to concentrate ourselves in cities? What is the value of cities? What do cities offer us? [...] %U http://www.mdpi.com/2078-1547/2/2/43