The development of Natural History, the science about wildlife and nature outside of civilization, is a landmark in contemporary culture. When men finally stop just using nature, and focus on studying it, they are able to uncover a whole new field of activities, which end up boosting tourism and entertainment. A new building of the Entertainment Complex, the Zoo, is developed to exhibit rare animals and plants so that buzy citizens that never go out in nature could actually see them. Finally, you gain 2 Envoys.