This is the headquarters of the Shingon sect and the residence of Kōya-san's abbot. The present structure dates from the 19th century. The main hall's Ohiro-ma room has ornate screens painted by Kanō Tanyu in the 16th century. The rock garden is interesting for the sheer number of rocks used in its composition, giving the effect of a throng of petrified worshippers eagerly listening to a monk's sermon.
Admission includes tea and rice cakes served beside the stone garden.