Starting at Barfüsserplatz, you'll open the Explorial app, enter the 6-digit game code that you received by text and Viator chat message, and step into Basel's compact old town. The tour is fully self-guided — no guide, no fixed start time, just your group and the city. The Tinguely-Brunnen performs first: nine mischievous machine-sculptures splashing away where a theatre stage once stood. Riddles move to their rhythm. Up by the Münster, the Pfalz terrace opens over the Rhine — swimmers drifting past in summer, Germany and France on the horizon. Trivia takes in the view. Then the Rathaus glows scarlet over the Marktplatz, its frescoed courtyard and golden tower daring you not to stare. Around two hours between fountain and river. Ferry across the Rhine afterwards — the leaderboard results travel well.