Moray, after processing of a Google Maps image
Moray is an archaeological site in Peru approximately 50 km northwest of Cuzco. The site contains unusual Inca ruins, mostly consisting of several enormous terraced circular depressions, the largest of which is about 30 m deep. Wiki reports a very interesting information: the depth and orientation with respect to wind and sun of the depression creates a temperature difference of as much as 15 °C between the top and bottom. According to Wiki "this large temperature difference was possibly used by the Inca to study the effects of different climatic conditions on crops. In other words, Moray was perhaps an Inca agricultural experiment station. As with many other Inca sites, it also has a sophisticated irrigation system."