The Gion Matsuri (Gion Festival) is an annual event in Kyoto on July 14 - 16. The festival have been going since 869 AD.
The downtown streets are shut to traffic and vendors set up booths to sell snacks and other goods. On July 16 a parade of Yamaboko floats takes place. As soon as the last float has passed, the situration returns to normal and the floats are disassembled and put away until next year.
It poured while we were there. A nice sunny day would have been better for both participants and spectators.