Starting at Plaça de l'Àngel in the Ciutat Vella, you'll open the Explorial app, enter the 6-digit game code that you received by text and Viator chat message, and vanish into the Gothic maze. The tour is fully self-guided — no guide, no fixed start time, just your group and the city. The Catedral de Barcelona rises first, gargoyles and all — and riddles want to know why exactly thirteen white geese live in its cloister. Then the Pont del Bisbe arches photogenically over Carrer del Bisbe. Trivia reveals it's younger than it looks, and darker too: find the skull and dagger hidden in the stonework. The Mercado de la Boqueria ends the route in full colour — fruit pyramids, jamón curtains and juice stands begging for a break. Around two hours in Europe's densest historic quarter. The leaderboard crowns the Gothic champion.