Starting at Plaza Azoguejo, right beneath the arches of the Roman aqueduct, you'll open the Explorial app, enter the 6-digit game code that you received by text and Viator chat message, and climb into the old town. The tour is fully self-guided — no guide, no fixed start time, just your group and the city. The route leads up through medieval streets to the Plaza Mayor, where the honey-coloured cathedral — nicknamed the Lady of Cathedrals — towers over café terraces and clue locations alike. At the far edge of the ridge waits the Alcázar de Segovia, part royal palace, part fortress, shaped like the bow of a ship sailing over the plains; its towers and legends fuel some of the trickiest riddles. On the way back, the Casa de los Picos shows off its wall of 617 granite pyramids — a 15th-century flex by a noble family, and an irresistible photo task. Roughly 2 hours door to door, cochinillo breaks not included. By the end, Segovia's skyline will read like a story you know by heart.