The transformation of cities is a challenge of global significance that will depend on the capacity to re-imagine the potential of cities, and thus needs more than standard technocratic urban planning approaches. Deep engagement with the arts provides one avenue for recasting the future of cities. This thesis explores the question of how ‘critical urban art interventions’ develop alternative ways of knowing urban nature, and the opportunities and limitations of using art to reimagine the future of cities. By drawing on urban political ecology and cultural geography, the thesis documents and explores the aims and tactics used in five urban art interventions to reimagine sites of urban nature in Stockholm. Qualitative interviews and participant observation were carried to explore these questions. Findings suggest that tactics used in urban art interventions promote embodied ways of knowing, and simultaneously interacting with the physical and socio- historical constructions of sites of urban natures.