Most of the Guanajuato’s architecturally significant buildings were built in the Mexican Baroque style because the mines were at their peak production during the 18th century, when this style was fashionable. This style can be found in mansions and civil buildings of that time, but the most ornate examples are churches, with intricate facades and altarpieces both of which often use the “estipite” column (inverted, truncated pyramid). 
A number of Baroque altarpieces from this time are also gilded with gold from the local mines. Within the city of Guanajuato, the most notable examples are the San Cayetano or La Valenciana Church, the Basilica of Guanajuato, and the Templo de San Diego de Alcantara.
At the beginning of the 19th century, Baroque was giving way to Neoclassical. The Mexican War of Independence ended most major constructions, but in many churches in the state, Baroque altarpieces were replaced with Neoclassical ones. A fine example of Neoclassical architecture is the Teatro Principal in Guanajuato.
UNIVERSIDAD DE GUANAJUATO (University of Guanajuato). Founded as an orphanage for educational instruction, it became a university in 1945. This edifice of green quarry stone reminds us of the magnificent European medieval designs. Located on Positos Street. Open Tuesday through Saturday from 10:00 AM to 2:00 PM and 4:00 PM to 6:00 PM, and Sunday from 10:00 AM to 3:00 PM. 
ALHONDIGA DE GRANADITAS (The Granary or Grain Depository). This building has a stark neoclassical façade. During Mexico’s War of Independence, a local hero known as El Pipila burned down the main door. Currently, the edifice houses the Guanajuato Regional Museum. Located at 6 Mendizabal Street. Open Tuesday through Saturday from 10:00 AM to 2:00 PM and 4:00 PM to 6:00 PM, and Sunday from 10:00 AM to 4:00 PM.
Click here for full article on www.best-of-mexico-travel.com
Source: http://www.best-of-mexico-travel.com/guanajuato-architecture.html
