Starting at Place d'Armes, beneath the Notre-Dame Basilica's twin towers, you'll open the Explorial app, enter the 6-digit game code that you received by text and Viator chat message, and step into Old Montréal. The tour is fully self-guided — no guide, no fixed start time, just your group and the city. Place Vauquelin comes early, its fountain squaring off between the grand Hôtel de Ville and the old courthouse. Riddles weigh the naval hero's legacy. The Marché Bonsecours gleams next — the silver-domed market that has been parliament, concert hall and city hall in its 175 years. Trivia browses the stalls. Then the Old Port opens up, with La Grande Roue de Montréal wheeling 60 metres above the St. Lawrence. Around two hours over cobblestones, en français ou en anglais. The leaderboard declares the winner — poutine celebrations recommended.