The mountain in the background is Mt. Hiei (比叡山), an 848-meter high peak that is home to many important and historic Buddhist temples.
Traditionally the Japanese have considered the northeast an unlucky direction. It is called "kimon" (鬼門), which translates as the "devil's gate," and it is the direction from which evil enters the mortal world. The presence of Mt. Hiei in the northeast was therefore one of the main reasons that Kyoto was chosen as an auspicious location for the capital after moving from the city of Nara more than 1,000 years ago: Mt. Hiei could block evil coming from that direction. To add an additional layer of protection a number of Buddhist temples were also established on the mountain, the most famous among them being Enryakuji (延暦寺) which was founded in 788 and is still a site of pilgrimage today.