Sannō Matsuri 山王祭
Sannō Matsuri (山王祭) or the Sannō Festival, is a major Shinto festival in Tokyo, along with the Fukagawa Matsuri and Kanda Matsuri. The Festival takes place annually in mid-June, but involves a procession called Shinkosai in even-numbered years only; annual celebrations encompass a number of activities and celebrations over a week, including the day-long Shinkosai (also called Jinkosai) parade through Nagatachō, Chiyoda, Tokyo.

| Location | Tokyo (東京都) |
|---|---|
| When | June (Summer — exact dates change every year) |
| Type | Tenka Matsuri |
| Official website | http://www.tenkamatsuri.jp/ |
Planning to go? The Sannō Matsuri is held in June, but the exact dates, times and any entry fees are set year by year. Check the official website for this year's schedule before you travel.
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Basic data from Wikidata (CC0). Description from Wikipedia (CC BY-SA), linked below. Details may change; the festival's official announcements are the authoritative source.