When thinking about a trullo, it’s often the white and grey trulli of Alberobello with their conical roofs that come to mind. While this is the typical (and possibly the original) form of a trullo, it is not the only form you can find. The trulli with conical roofs are found more towards central and northern Puglia, while the trulli of southern Puglia and the Salento area tend to have flat roofs. In the areas where conical roofed trulli are found, the weather tends to be wetter and it snows in the winter. A conical roof makes it easier for water and snow to slip off the roof, while strong sun in the southern part of Puglia makes this roof shape unnecessary. The weather in the far south brings a shorter rainy season and it snows very rarely. Instead the trulli feature flat, slightly tilted roofs that allow rain water to drain away and often into a built-in gutter that runs down the side of the structure. But, almost all trulli feature the district rounded walls that add to their uniqueness.