Like so many metropolises across the world, Barcelona is struggling to reconcile the urge to develop with a pressing need to protect its stretched natural resources against existential threats. The Llobregat Delta epitomises this struggle, having continuously lost ground to urban sprawl from one century to the next. If the expansions to the port and airport proceed as planned, then the delta could be disfigured beyond recognition. The Manifesta 15 cluster Balancing Conflicts thus highlights the need to balance growth with preservation. The cluster’s main venue is Casa Gomis, a modernist villa whose history is intertwined with that of Barcelona’s cultural avant-garde, making it a nerve centre for the ongoing discourse on sustainability and modernisation.