The city is the administrative center of Otsu Shiga Prefecture. In II and VII centuries in Otsu even briefly became the capital of the state. Change of capital usually takes place after the death of the former emperor. Thus, in 667, the imperial court moved from Asuka in Otsu, who for five years carried out capital functions. Then the yard again changed their place of "dislocation" and Otsu became a postal station on the Tokaido lively tract.

In the year 686 in Otsu was founded the first major Ondzёnzdi Monastery, also called Mii-dera and belonged to the Tendai Buddhist School. One hundred years later near the Mii-dera, on Mount Hiei on the orders of Emperor Kammu was built another temple - enryaku-ji, also belonged to the Tendai sect, but to its other branches. This temple was built for the purpose of spiritual protection for what was then the capital of Kyoto, and it was intended to protect her from evil spirits who came from the north-east.

Monk-founder enryaku-ji became Saicho, created Tendai. In its heyday, the temple complex enryaku-ji included 3,000 temples, the monastery is considered very popular among the Japanese nobility, getting good income, owned real estate all over the country and had some privileges. Students Saicho after 12 years of spiritual practice received positions in the government.

Enryaku-ji inhabited quite warlike monks who, if necessary, take up arms, and did not hesitate to solve their problems with it. Enryaku-ji was considered the main temple of the Tendai sect, and Mii-dera - more powerful and rich. Monks in two monasteries for five centuries (from X to XV century) in a state of armed confrontation, raiding each other, during which destroyed or set fire to one and then another monastery.

In 1571, in the war intervened ruler of Oda Nobunaga, also fire and sword to pursue a policy of association of Japanese land. He laid siege to the monastery enryaku-ji, crushed and burned most of its buildings. In the middle of the XVII century of the restored buildings, including the main prayer hall. His current building is recognized in Japan, the third largest wooden building and noted the status of national treasure.

Currently, the temple complex of the monastery is divided into three parts. The most interesting sights can be seen in the eastern (Todo) and western (Saito) parts. The third part, Ёkava considered remote and less interesting.