In an age which has been called the ‘empire of the ephemeral’, ephemeral urbanism is today a necessity, a choice and a symptom, calling into question our habitual conceptions of urbanism and revealing resistance, rituals, disasters, dramas and divergence. Felipe Vera, a Chilean architect and curator, a specialist in themes relating to temporary cities, who, with the Indian architect Rahul Mehrotra, took part in the 2016 Venice Architecture Biennale, talks to us about the other vision of these cities that flow like Heraclitus’ river of time.