Starting at Bahnhofplatz 4, by Würzburg's main station, you'll open the Explorial app, enter the 6-digit game code that you received by text and Viator chat message, and head for the old town. The tour is fully self-guided — no guide, no fixed start time, just your group and the city. At the Alter Kranen, the baroque twin crane that loaded wine barrels onto Main river barges for over a century, the riddles begin with a close look at 18th-century engineering. On the Alte Mainbrücke, you'll walk between twelve giant stone saints with the Marienberg fortress rising across the water — and if locals are sipping a Brückenschoppen of Franconian wine, feel free to join them after your clue. The grand finale builds toward the Residenz, the palace so lavish Napoleon allegedly called it the loveliest parsonage in Europe, its facade full of quiz-worthy detail. Plan for about 2 hours with breaks as you please. By the end, Würzburg will have earned a permanent spot in your travel stories.