On the ninth day of my walk along the Shikoku Pilgrimage, after leaving temple 22, Byodo-ji, I took the main road heading for the coast of Tokushima. After spening 100 days on Mount Tairyuji Kukai must have taken the same route because a sign pointed to Iyadani Kannon, a little detour off the main road and a site supposedly founded by Kukai.
Apparently he left "7 Wonders", one of them being this large rock that is supposed to be balanced in such a way that a single finger can cause it to rock.
There were some interesting old statues and some rock carvings.
Everything was moved to this current location when the nearby dam and reservoir were created.
Well worth the little detour, and a nice break from the main road. The sign pointing to it is a couple of kilometers past Awafukui Station on Route 55.