The city of Trieste has been filled with ageing urban fabrics and abandoned industrial buildings due to obsolescence. Witnessing the decay of the city excusably provoked the pessimism of the locals as it made them conscious of the fact that their life and pride are degrading. The negative labels associated with decay inevitably seized the general definition and cognition. However, deterioration can only be understood as one of the superficial readings of the phenomenon of decay. As depicted in many arts and literature, decay does have its only poetics, aesthetics and intrinsic values that embellish and complement the urban environment and memories. Meanwhile, the degeneration of architecture with symbolic values, be it an intentional or inadvertent incident, would implicate significant political messages and ideas to the society. In the case of Trieste, the meanings of this natural (and occasionally artificial) process are still to be explored and discussed. Is there a possibility that decay could be considered a constructive phenomenon that can sublime as a form of regeneration for the ageing city? The project would then be an experiment that attempts to embrace the material processes, aesthetics and the spatial and programmatic potentials informed by the phenomenon of decay. It searches for alternative answers to the preestablished architectural typologies, meanings and purposes through rethinking on the current preservation approaches and alternative possibilities in dealing with ruins and abandoned buildings in Trieste. As a result of the quick and efficiency-oriented manufacture in the industrial past, architectural obsolescence brought in new artificial materiality and ways of decomposition to the discourse of decay, which are unprecedented in the pre-industrial time. The expansion of the definition of decay implies the misfit of conventional treatments on modern ruins in the post-industrial era. Delving into the phenomenon of decay may introduce a different set of aesthetic/tectonic languages and spatial qualities to the decaying waterfront of Trieste.