The regard for a natural environment is also consistently reflected in secular building. In the Heian period complex building schemes, known as shinden-zukuri, were devised for the court nobles. A number of elegant rectangular houses were joined by long corridors that surrounded a landscaped garden and pond. During this period the standard for domestic architecture was set and has been maintained to the present day. The principal style of Japanese dwelling of the upper class is unexcelled for its refinement and simplicity.
Interior posts form a supporting skeleton for the roof.
The exterior walls usually consist of movable panels that slide in grooves. Important rooms are provided with a tokonoma, an alcove for the display of a flower arrangement and a few carefully chosen objects of art. Often a separate space is set aside for the tea ceremony, either incorporated within the house or constructed as a pavilion in the garden. An important development of the late 16th cent. Fortified castles, of which one still exists at Himeji, were based on the European donjon and were erected on high bases formed of enormous stone blocks.