Abstract
Hie-Taisha, one of the most historical and biggest Shinto-shrine, is famous for its characteristic form of three Honden (main sanctuary of the shrine) called Hie-zukuri. Another important point is that seven Honden including three Hie-zukuri-Honden have rooms named Geden under the main floor. This paper tries to make clear this architectural construction by paying attention to the plan of main floor rooms and under floor rooms, and tries to clarify the situation of Geden before Meiji Restoration. The summary of brief actual measurements and investigations of several old records is as follows : (1) Hie-zukuri-Honden and Sangenshanagare-zukuri-Honden have a common form related to Geden. (2) Several Geden existed already in middle Kamakura-era. Then the room under the floor was called Geden or Shitadono, and was used to shut oneself up for praying the Gods of Shinto and Buddhism. (3) This architectural construction is the most particular and considerable expression of Shimbutsushugo (the thought connecting Shinto with Buddhism) in Japan.