No trip to Guanajuato is complete without discovering its legendary subterranean streets! Originally 16th-century mining tunnels, this labyrinthine network was transformed into a unique roadway system beneath the city. Walking through these stone-vaulted passages, you'll be surrounded by colonial-era charm, with vibrant murals and spontaneous street performances around every corner. Don't miss the tunnel section near Alhóndiga de Granaditas Museum, where dramatic lighting creates the perfect Instagrammable moment. It's like stepping into a living history book with a bohemian twist!