Zenkō-ji is a Buddhist temple located in the city of Nagano, Japan. The temple was built in the 7th century. The modern city of Nagano began as a town built around the temple.
Historically, Zenkō-ji is perhaps most famous for its involvement in the battles between Uesugi Kenshin and Takeda Shingen in the 16th century, when it served as one of Kenshin's bases of operations. Currently, Zenkō-ji is one of the few remaining pilgrimage sites in Japan.
Zenkō-ji was founded before Buddhism in Japan split into several different sects. It currently belongs to both the Tendai and Jōdoshū schools of Buddhism, and is co-managed by twenty-five priests from the former school, and fourteen from the latter. The temple enshrines images of the Amida Buddha. According to legend, the image, having caused dispute between two clans, was dumped into a canal. It was later rescued by Honda Yoshimitsu. The temple was thus named "Zenkō," according to the Chinese transliteration of Yoshimitsu's name.
The main Buddhist image is a hibutsu, a hidden Buddha statue, not shown to the public. This hibutsu is rumored to be the first Buddha statue to ever be brought to Japan.