Starting at 35 Beaumont St in central Oxford, you'll open the Explorial app, enter the 6-digit game code that you received by text and Viator chat message, and set off into one of England's most storied cities. The tour is fully self-guided — no guide, no fixed start time, just your group and the streets. The route leads you first to the Radcliffe Camera, the stunning circular library that has defined Oxford's skyline since 1749. The riddles here will test your knowledge of the city's academic history and the architectural quirks that most visitors walk right past. Next up is the Narnia Door — a carved wooden entrance tucked into the university grounds that inspired C.S. Lewis's most famous creation. The clues will ask you to look closer than most tourists ever do. The tour finishes at the Bridge of Sighs, Oxford's neo-Venetian crossing linking Hertford College's two buildings. It's one of the most photographed spots in the city, and the riddles add a layer of history that the photos never capture. Allow around 2 hours to enjoy the walk without rushing. Oxford has centuries of surprises — this tour makes sure you find them.