Starting at Plaza de Sas in the Casco Antiguo, you'll open the Explorial app, enter the 6-digit game code that you received by text and Viator chat message, and weave into the old town. The tour is fully self-guided — no guide, no fixed start time, just your group and the city. The Basílica del Pilar soon fills the skyline with domes and towers above the Ebro. Riddles find the Goya frescoes and the two unexploded bombs still on display. At the Plaza del Justicia, trivia recalls the Justicia de Aragón, the medieval office that dared to check the power of kings. Then the Catedral del Salvador — La Seo — closes the circuit, a single cathedral wearing Romanesque, Gothic, Mudéjar and baroque all at once. Around two hours through Caesar Augusta's descendants. The final ranking is announced without a single cannonball.