The post office is made with a very light-colored, almost translucent variety of a stone called "chiluca." The exterior is covered in decorative details such as iron dragon light fixtures and intricately carved stone around the windows and the edge of the roof.[2] Much of the metal work around the windows and other parts of the facade highly polished brass, which was made in Italy. An example of the building's complicated design is that each of the floors has windows of a different architectural style.