Mount Hiei rises between Kyoto and Lake Biwa, and in 788 a young monk named Saichō built a small hermitage on its slopes. It grew into Enryaku-ji, the headquarters of the Tendai school of Buddhism and one of the most powerful religious institutions in Japanese history. Many of the founders of later Buddhist schools, including Hōnen, Shinran, Dōgen and Nichiren, studied here. At its height, the mountain held thousands of temples, and the monastery maintained an army of warrior monks who regularly descended on Kyoto to intimidate the court. In 1571, the warlord Oda Nobunaga, tired of their political meddling, attacked the mountain, burned the temples and killed thousands of people. The monastery was rebuilt in the following decades, and today its halls are spread across the forested summit in three main areas, connected by footpaths and roads. The main hall, the Konpon Chūdō, houses a lamp said to have burned continuously for over a thousand years. Enryaku-ji is part of the UNESCO listing of the Historic Monuments of Ancient Kyoto.
The mountain is still a place of rigorous practice. A small number of monks undertake the kaihōgyō, a pilgrimage of a thousand days spread over seven years, walking enormous distances around the mountain, sometimes the equivalent of a marathon a day, in straw sandals. Those who complete it are revered as living saints.
The ride up is a joy. The Hieizan Driveway, a toll road, climbs from the Kyoto side in a series of smooth, well-cambered bends through cedar forest, with views over the city, and continues as the Okuhiei Driveway along the ridge to the north, with views over Lake Biwa, the largest lake in Japan. The surface is excellent, the traffic light on weekdays, and the scenery superb. Watch for deer and monkeys, especially at dawn and dusk. Ōtsu, on the shore of the lake, is the other gateway to the mountain, with a cable car up from Sakamoto, a village of old stone walls built by the monks' masons.
Ōtsu and Kyoto have fuel and every service; there is little on the mountain itself. Winter brings snow to the summit, and the toll roads may close. Spring and autumn are the best seasons, and the forest is cool even in summer.