Fire Altar
The area inside the fence was used for goma fire ceremonies. Various items and prayers are offered to Fudo Myo-o, one of the five Wisdom Kings, by burning them in a sacred fire. The goma fire ceremony originated in India and is practiced in Japanese Esoteric Buddhism, such as the Shingon and Tendai schools, and in the mountain-worshipping religion of Shugendo. The fire is thought to cleanse impurity and protect from harm. The sacred fire was contained in a round, bowl-shaped stone that is now underneath the small, moss-covered mound near the center.
The four stone columns standing at each corner would have been used to suspend a rope to mark the sacred space. Most goma altars have two taller columns toward the front, where the officiant sits, and a rope is suspended between them. This altar is a rare exception because there is a Shinto torii gate instead of the taller poles.
The statue on the large stone directly behind the fence is of Fudo Myo-o. Images of Fudo Myo-o are usually surrounded by flames, represented here by the jagged edges of the slab behind him.
This area is part of Rinnoji, a temple of the Buddhist Tendai school. Religious practice at Nikko has been a syncretic mix of Shinto, Buddhism, and Shugendo since the eighth century. Even so, a Shinto torii appearing in the sacred space for this type of fire altar is extremely unusual.