Starting at Plaza Nueva, Granada's oldest square, you'll open the Explorial app, enter the 6-digit game code that you received by text and Viator chat message, and slip into the streets below the Alhambra. The tour is fully self-guided — no guide, no fixed start time, just your group and the city. The Catedral de Granada soon fills the sky — the Renaissance colossus the Catholic Monarchs ordered over the city's great mosque, with their tombs next door. Riddles handle the dynasty. The Corral del Carbón follows: the 14th-century merchants' inn, the only complete one left in Spain, its horseshoe gate worn smooth by centuries of trade. Then the Alcaicería tightens into a lattice of lanes — the old silk market reborn as a bazaar of lanterns, ceramics and clues. Around two hours through Moorish and Christian Granada entwined. The leaderboard settles accounts — tapas come free with the celebration, as Granada insists.