built in locations favored by the precepts of Chinese geomancy. The arrangements not only of the buildings, groups of trees and ponds of the compound, but also of mountains and other geographic features in particular directions around the temple played important roles as well. The Chinese five elements school of thought believed that many natural phenomena naturally fell under five categories. Six groups of five categories were established as a rule to the building of edifices. A palace for a new prince would for example be placed east to symbolize birth, and yellow tiles would be used for the imperial palace to symbolize power. The five elements theory is also the basis of the gorintō, an extremely common stone stupa whose invention is attributed to Kūkai. Its five sections (a cube, a sphere, a pyramid, a crescent and a lotus-shaped cusp) stand each for one of the five elements. Chinese numerology also played an important role. According to the Yin-Yang school, which started in about 305 BC, Yang stood for the sun, warmth, maleness and odd numbers, while Yin stood for their opposites. In groups of buildings, therefore, halls occurred in odd numbers because halls themselves were believed to be Yang. Being Yang, odd numbers in general are considered positive and lucky, and Buddhism shows a preference for odd numbers. In the case of storied pagodas, either in stone or wood, the number of stories is almost always odd. Practically all wooden pagodas have either three or five-stories. Specimen with a different number of stories used to exist, but none has survived. Because of fire, earthquakes, typhoons and wars, few of those ancient temples still exist. Hōryū-ji, rebuilt after a fire in 670, is the only one still possessing 7th-century structures, the oldest extant wooden buildings in the world. Unlike early kami worship shrines, early Buddhist temples were highly ornamental and strictly symmetrical (see reconstruction of Asuka-dera above). Starting with Hōryū-ji in the late 7th century, temples began to move towards irregular ground plans that resulted in an asymmetric arrangement of buildings, greater use of natural materials such as cypress bark instead of roof tiling, and an increased awareness of natural environment with the placement of buildings among trees. This adaptation was assisted by the syncretism of kami and Buddhism, which through Japanese traditional nature worship gave Buddhism a greater attention to natural surroundings. During the first half of the