Are Puebla, Guanajuato or San Miguel de Allende worth adding?
They are worth adding when you want Mexico’s inland city texture: architecture, plazas, food and slower streets. They should not be added just to avoid an empty-looking route between bigger commitments.
Answer
Puebla, Guanajuato and San Miguel de Allende can all add a different inland rhythm to a Mexico trip, especially for travellers who enjoy plazas, churches, architecture, markets and cities that work by wandering rather than spectacle. The danger is treating them as mandatory seasoning. If the main route is already Mexico City, Oaxaca and a beach, adding more cities may dilute the trip rather than deepen it. Choose one when it changes the journey: Puebla for a stronger CDMX-side extension, Guanajuato or San Miguel when central-highland texture is part of the point.