It measures 72 by 68 metres, with a height of 23 metres, and occupies an area of 4,828 square metres. It is constructed on the side of a hill and two of its sides are surrounded by elevations. There are no ornamental facets on the exterior, except for a few windows at the top of each storage room. It has cornices built in a Doric style, constructed with two types of regional stone—reddish and greenish. This gives it a curious appearance, resembling a stronghold or a castle, which it has come to be called by the people of Guanajuato. In the interior, there is a porch that leads to a spacious central patio. The porch contains Tuscan columns and adornments. There are two staircases that lead to the upper floor. The Grain Exchange building has only two access doors, a small one facing the east, adorned by two columns, and a large door of the same basic style, facing the north. The edifice was used for the buying and selling of wheat, corn, and other grains. Prior to the Mexican independence from Spain, it was used as a warehouse, military barracks, and prison. Currently it serves as a regional museum.