Event tradition of Nara in Japan. (Prescribed burn of Wakakusa)

Mount Wakakusa (Wakakusa-yama), also known as Mount Mikasa (Mikasa-yama), is a 342 m (1,122 ft) high mountain located in Nara, Nara Prefecture, Japan, to the east of Nara Park.
On the fourth Saturday of each January, the dead grass of Mt. Wakakusa is burned in an annual festival known as Yamayaki (literally "mountain roast"; common translation: "prescribed burn").  The tradition supposedly originated from a boundary dispute between two temples, Todai-ji and Kōfuku-ji in 1760. As the mediations failed, the entire mountain was set ablaze. Other explanations suggest the extermination of wild boars or pests as a result. The festival today begins with a ceremonial igniting by members of both temples, followed by a fireworks display. The festival has been postponed due to poor weather in the past.

Usually.