Besieged Chang'an is a participatory art project consisting of a series of historical archiving, interviews, photography and presented in the form of an immersive theatre on the relics of a royal palace of the Tang Dynasty. The project seeks reflections on the nostalgia complex for the city’s golden age still commonly held by citizens today, which results in both over-romanticizing the history and the self-pity enrooted deeply in our collective mentality. As an iconic monument bearing both glory and sorrow, the site is turned into an interface with different scenes spatially juxtaposing and temporally alternating on it, inviting citizens to join in as different roles that build the whole play. During the audiovisual show, projected ancient images and pre-recorded lyrics gradually give way to silhouettes and live reciting of the participants themselves. As the narratives move from ancient to contemporary settings, several controversial issues in recent years that have once thrust this historical city into the spotlight are rediscussed, with some inherited defects recurring in that tragic millennium cycle reflected. By taking on roles of different historical characters and contemporary stakeholders with their respective images and testimonies, participants are exposed to a more objective panorama of disasters in the history of the city, where such emotional engagement and critical detachment jointly promote parrhesia and awareness of responsibility embedded in each individual’s citizenship.