The 10-year-long renovation of Paris’ worldwide known shopping mall and transportation hub, Les Halles, is about to be completed. Take an eye-popping look at Europe’s biggest construction site. With a budget of 800 million euros, the architects David Mangin and Patrick Berger have the heavy task of inventing the Halles of the 21st century. But there is a constraint: the Halles must remain open to the public during the works.