Back-to-school season means tucking away the flip-flops and lacing up the sneakers… and setting off to explore the capital’s hidden treasures. The spotlight is on the European Heritage Days, September 19-20, 2026, when museums, castles, and offbeat spots throw open their doors wide. In Paris, don’t miss Maison La Roche, a modernist masterpiece by Le Corbusier, a (re)discovery in the chic 16th arrondissement.