is of "particular importance[...] because the word contained the meaning 'island. Furthermore, the principle of , or "obeying (or following) the request of an object", was, and still is, a guiding principle of Japanese rock design that suggests "the arrangement of rocks be dictated by their innate characteristics". The specific placement of stones in Japanese gardens to symbolically represent islands (and later to include mountains), is found to be an aesthetically pleasing property of traditional Japanese gardens. Thomas Heyd outlines some of the aesthetic principles of Japanese gardens in Encountering Nature: Rock placement is a general "aim to portray nature in its essential characteristics" – the essential goal of all Japanese gardens. Furthermore, Heyd states: Such attention to detail can be seen at places such as Midori Falls in Kenroku-en Garden in Kanazawa, Ishikawa Prefecture, as the rocks at the waterfall's base were changed at various times by six different . In Heian-period Japanese gardens, built in the Chinese model, buildings occupied as much or more space than the garden. The garden was designed to be seen from the main building and its verandas, or from small pavilions built for that purpose. In later gardens, the buildings were less visible. Rustic teahouses were hidden in their own little gardens, and small benches and open pavilions along the garden paths provided places for rest and contemplation. In later garden architecture, walls of houses and teahouses could be opened to provide carefully framed views of the garden. The garden and the house became one. Garden bridges Bridges first appeared in the Japanese garden during the Heian period. At the Byōdō-in garden in Kyoto, a wooden bridge connects the Phoenix pavilion with a small island of stones, representing the Mount Penglai or Mount Horai, the island home of the Eight Immortals of Daoist teaching, The bridge symbolized the path to paradise and immortality. Bridges could be made of stone (), or of wood, or made of logs with earth on top, covered with moss (); they could be either arched () or flat (). Sometimes if they were part of a temple garden, they were painted red, following the Chinese tradition, but for the most part they were unpainted. During the Edo period, when large promenade gardens became popular, streams and winding paths were constructed, with a series of bridges, usually in a rustic stone or wood style, to take visitors on a