Pizarro commissioners chosed the Rímac valley because it was considered a healthy and airy place with good lands to farm, plenty of firewood and Indian labor, besides near to the sea. However, over time, Lima was gaining a reputation for having an unhealthy climate. The combination of moisture and heat easily decompose matter and was considered unhealthy. Soon realized that this combination was not good and gain a fame of unhealthy climate and with miasma. The "muladares", rubbish, ditches, drains infested the air with unhealthy effluvia that were thought created diseases and pests. Throughout the colony(1535-1821), the idea that the miasma and the wet weather increased the generation of pests were sustained and supported by doctors and disseminated by scholars and travelers who lived or passed through the city.