Bow your head, say a prayer and maybe even light a candle in Tula Cathedral. This important place of worship may not always be accessible, so check ahead for hours if you'd like to see inside.
You'll be spoiled for sightseeing choice when visiting Tula de Allende. Tula Cathedral is a good place to begin here, but there are loads of other interesting places to discover. Tula Archaeological Site, Tula National Park, and Quetzalcoatl Historical Room are not far from the principal church and will fill in your day nicely.
