Mii-dera, formally called Onjō-ji, is a Buddhist temple located at the foot of Mount Hiei, in the city of Ōtsu, in Shiga Prefecture. It is only a short distance from both Kyoto, and Lake Biwa, Japan's largest lake. The head temple of the Tendai Jimon sect, it is something of a sister temple to Enryakuji, at the top of the mountain, and is one of the four largest temples in Japan. Altogether, there are 40 named buildings in the Mii-dera temple complex.
Mii-Dera is temple number 14 in the Kansai Kannon Pilgrimage. Onjō-ji was founded in the early Heian period. The temple was founded in 672 following a dispute over Imperial succession. Emperor Tenji had died, and his son was killed by Tenchi's brother, who was then enthroned as Emperor Temmu. Temmu founded Onjō-ji in honor and memory of his brother.