Tamagawa Daishi

The official name of Tamagawa Daishi is Hosenzan Gyokushinin.
It is a temple of the Chizan branch of the Shingon sect.
It was founded in the Taisho era, with the Daishido Hall built by the great monk Ryukai. After that, an underground Buddha hall was constructed in 1934, taking six years.
The underground Buddha hall is located 5 meters below the ground and is a 100 meter long worship hall made of reinforced concrete, making it one of the most unique underground sacred sites in Japan.

Okuno-in Underground Sacred Site Hensho Kongo-den
This Buddhist hall represents the womb of the gigantic “Secret Buddha Dainichi Nyorai,” the source of our life. From directly below the main hall to the entire underground area of the temple grounds, it welcomes all the Daishi and Kannon deities of 88 sacred sites in Shikoku and 33 sacred sites in the western part, making a connection with those who are related to us.
If you practice worship with sincerity and devotion, your body and mind will be purified, and you will be basked in the infinite mercy of Buddha, which will give you the power to live and happiness.