Apprenticeship is an important process, developed in medieval societies in order to put the economy on a more professional footing. The specialization of workers into different crafts helps make them much better; and the tradition to introduce "apprentices" from a young age into the craft helps transmit the secrets of the craft to the next generation. Thus, a whole new specialty District - the Industrial Zone, is created, and in its special building, the Workshop, master craftsmen can work without bothering the other citizens. What´s more, the operation of the most important industrial improvement, the Mine, is vastly improved.