The first few miles of the pilgrimage path, from temple 1 to temple 3, are along asphalt, but not long after temple 3 the way follows a small footpath that snakes across ride paddies and then through some bamboo groves before arriving at the small temple of Aizen-in.
Both the main gate and the entrance to the main building are flanked by huge straw sandals, and inside the main building are thousands and thousands of regular-sized sandals in piles.
In a corner is a pile of crutches and leg braces which people have left here after having had lower-body ailments healed. The temple was supposedly founded by Kukai who also carved the statues of the main deity, Fudo Myo-o.
Aizen-in is the Okuin of temple 3, Konsenji. Okuin means "inner hall" and is the building of a temple that is furthest from the entrance gate. This one is about 3k from the main temple.