In its second edition, the Seoul Biennale of Architecture and Urbanism establishes a global platform in order to study new collaborations and models, exchange information, and encourage discussion. Themed Collective City, it serves as a basis for the residents of Seoul to reclaim their city and redefine its architecture, and uses new, experimental methods of communication with the public. This catalogue not only provides an overview of the different exhibitions but also the various scenes of participation in public programmes, offering urban and architectural perspectives on participants, projects, and outcomes, aiming to pave the way for the implementation of new policies.