One day
Start at the great pink Cathedral and its plazas, then walk the centre — the Palacio Clavijero courtyard, the Colegio de San Nicolás, the arcaded Portales — and dip into the Mercado de Dulces for ates and sweets. After a carnitas or sopa tarasca lunch, stroll east to the aqueduct and along the Calzada, find the Callejón del Romance, and — if it's a weekend — come back for the cathedral's evening light-and-fireworks show.