Can temporary architecture change the way we experience culture? In the last few decades, museums, galleries and cultural institutions have increasingly used pop-up structures so that a wider audience can enjoy art and heritage. These lightweight, removable and reconfigurable structures are not merely exhibition spaces, but stunning immersive experiences that attract the public and have rapidly become widespread on the web or through social media. Their visual impact and their ability to amaze onlookers often requires the use of avant-garde building solutions and innovative materials, thus turning them into experimental architectural prototypes. But how is it possible to combine their ephemeral nature with the concept of sustainability? This publication tackles this challenge by analysing the environmental, economic and social impact of these structures in search of strategies that will make them more sustainable. In a journey that includes flexible design and future scenarios, it provides a multidisciplinary analysis, enriched with an extensive repertoire of case studies; the objective is to promote good practices for a more conscious and responsible architecture.