The Festival of the Steel Phallus.
Japan 4K originally shared:
Kanamara Matsuri かなまら祭り, or Festival of the Steel Phallus in English, is one of the more unusual festivals in the world. It is held every year on the first Sunday in April, in the city of Kawasaki, during the cherry blossom season This religious celebration of the penis has roots in the early 1600s, in the Edo period of Japan. At the time it was a frequent stop for travellers and traders who were close to the capital and to completing their journey. As is typical for these types of towns, many tea houses sprang up to entertain and distract the weary travellers; as can be imagined, tea was not the only thing on offer. The girls that would service the travellers started going to a local Shinto shrine to pray for protection from sexually transmitted diseases, which slowly evolved to become a yearly festival celebration.
Like any good festival that has been around for a while, it also has a more imaginative founding story (check out the Ivrea Battle of the Oranges for another example of a creative festival myth). The tale goes that the innkeeper's daughter was soon to marry. An evil demon, upon hearing the news, decided to ruin the celebrations by crawling into the girl's lady parts. Terrified, the girl stayed silent, so that on her wedding night, when her husband tried to consummate the marriage, the demon decided to snack on the poor man's penis. This happened one more time to another suitor, before an ingenious blacksmith thought up a clever solution. He cast an iron penis, and used it as bait. The demon, thinking he had found another sucker to castrate, bit down sharply, and to his surprise found out that it was made out of metal. The demon fled, hurt and humiliated, and everything ended happily ever after with the girl marrying the blacksmith. To this day, an enormous iron penis is the primary shrine at the Kanamara Matsuri.
The money raised goes to funding HIV awareness and research.