The recent emergence of the "urban commons" is associated with the "exclusion" problems of modern cities, which are enmeshed in the mechanism that spatially excludes those who are incapable of paying the market prices. Cities are also tightly regulated by various government regulations that control people's actions, and creative practices are often stifled. The excluded not only resist commercialization, privatization, and state laws but also crave and pursue their own space and lifestyle. This study argues that the urban commons is a "haven" where the excluded are protected, existing as an alternative that outreaches the state and market ambits. We examine a Korean case to see how urban commons are created to embrace the excluded, focusing on the settings and process. The results show that (1) social exclusion and a power rift between the market and state during the urban process constitute the settings in which communities of the excluded create urban commons as a haven; (2) the creation and maintenance process should not only meet Ostrom's design principles but also requires urban commoners to practice commoning as an alternative lifestyle; and (3) the urban settings pose threats to meeting the process requirements, so appropriate strategies should be employed to bridge the gaps.