Starting at Parc de Milan, Pl. de Milan, 1007 Lausanne, Switzerland, open the Explorial app and enter the 6-digit game code that you received by text and Viator chat message. The riddles take you down toward the lake and through the Olympic quarter that has made Lausanne the capital of world sport. The first clue leads you along Boulevard Grancy, one of Lausanne's grand residential avenues lined with elegant 19th-century apartment buildings and mature plane trees — a reminder that this city was building in style long before the Olympic committees arrived. Next, the app guides you to L'horloge olympique, the Olympic clock near the lakefront — a ticking monument to the city's role as the official home of the Olympic movement since 1915. From there you find Le feu olympique, the Olympic flame installation on the lakefront, whose symbolism draws visitors from across the world and whose setting — with Lac Léman and the Alps beyond — is quietly spectacular. Around 2 hours on foot, including a gentle descent toward the lake. The return uphill is the only effort required.