Mount Hiei, at the northwest edge of Kyoto, is home to one of Japan’s largest temple complexes, a UNESCO World Heritage Site. Construction began in 788 C.E. by the monk Saicho, who is also credited as founder of the Tendai school of Buddhism. Over time, the entire top of the mountain became covered with temples, and the resident monks were far from meek and humble: They would raid Kyoto, battling imperial forces to ensure their religious rights. You can easily spend all day wandering the monastic buildings; just make sure not to miss the Enryakuji, the main temple, which has an incense smell not to be matched anywhere, and the sense that the temple itself is humming mantras. Hike up the mountain or take the cable car, but anticipate that once there, you’ll want to stay a while.