This picture is a ceiling of a traditional Persian bath in Yazd city in Iran. The technique used to construct this ceiling is called ''karbandy''. In this method, intersecting arches are built in a way to create a shape like a sun in the middle. Then the gaps between arches are filled, and above the hole in the middle of the ''sun,'' a small dome is built. This little dome contains windows in it to ventilate the air in the bath and let the sunlight comes into the place.