The Alhóndiga de Granaditas was another important place early in the Mexican War of Independence. After El Pipila burned the door, the place was overrun and hundreds of people hiding inside were killed, including members of Spanish and Creole families living in Guanajuato. Since the town was a major mining place it had many wealthy citizens (and that wealth served to highlight the poverty of the miners who died to get it out).
Four of the main leaders (Hidalgo, Allende, Aldama, and Jimenez) of the insurgents were captured the next year and executed. Their heads were hung on each corner of the Alhóndiga de Granaditas and left there for 10 years until the war was over and Mexico was independent.
There is a whole lot more to this story, but that's specifically what happened in this particular building in 1810 and 1811.
I don't have any photos from the inside since there was an addition fee for the camera. There were some murals and many displays and it was an interesting museum.