For a visit to where Herradura tequila is made, go to San José del Refugio. It's a spectacular old hacienda where you can see workers' quarters from long ago. The tour ends with a tasting of some of the different tequilas you can purchase in the gift shop. Tours are scheduled during weekdays on the hour from 9 to 3. Just to be safe, call ahead for reservations.
Comercio 172, Tequila, 45380, Mexico