The present Kondo (Main Hall)
is the 6th reconstruction in 1932. It is an irimoyazukuri (hip and gable construction) building. The principal image is a hidden Buddhist image and it had never been open to the public. However we can see "Yakushi Nyorai Statue" of the principal image for the first time from Apr,2nd to May.21st. It is made by Takamura Koun and is almost like a white statue between two attended figures "Fudomyoo." Unnfortunately I can't show you a picture of Yakushi Nyorai Statue because of no photograph.
The Chumon (The Middle of The Gate)
When I visited Koyasan last year, Chumon was under reconstruction and I couldn't see it. This time the rexonstrucrion was finished and could see the beautiful Chumon. The four guardian kings are standing inside the Chumon. They are Jikokuten, Komokuten, Zochoten, and Tamonten. They guard the east, the west, the south and the north respectively.
If you are interested in Koyasan, please refer to KOYASAN : The Sacred Center of Shingon Buddhism.