Mount Hiei (Jp. 比叡山 Hiei-zan) is a mountain to the northeast of Kyoto city, lying on the border between the Kyoto and Shiga prefectures, Japan.
The temple of Enryakuji, the first Japanese outpost of Tendai sect of Buddhism, was founded atop Mt. Hiei by Saicho in 788. The temple complex was razed by Oda Nobunaga in 1571 to quell the rising power of the Tendai's warrior monks, but it was rebuilt and remains the Tendai headquarters to this day.
External link
Wikitravel: Mount Hiei (http://wikitravel.org/en/article/Mount_Hiei)
From 1181 to 1201, during the period of his entry as a child into the Order and life on MountHiei, 20 years of traditionalism and ardent practice culminated in a religious dissatisfaction which led him down from MountHiei to seek a new path.
On MountHiei, rather than achieving high ecclesiastical status as depicted in tradition, Shinran is revealed in his wife Eshin-ni's letters (discovered only as recently as the 1920's) to be a Doso, a priestly functionary in the Hall of Continuous Nembutsu in the monastery.
According to Eshin-ni, when he came down from MountHiei, convinced he was a failure, and filled with deep religious dissatisfaction and despair, he confined himself in Rokkakudo for 100 days.