Held annually on the first Sunday of April at Kanayama Shrine in Daishi-ku, the Kanamara Matsuri (Festival of the Steel Phallus) draws enormous crowds including many international visitors. The festival has roots in Edo-period rituals connected to fertility, safe childbirth, and protection against sexually transmitted disease — the shrine was traditionally associated with sex workers from the nearby Kawasaki-juku post town.
Today's event is noisy, colourful, and good-humoured: phallus-shaped lollipops and carvings are sold alongside more conventional festival food, and participants carry portable shrines through the streets. The atmosphere is festive rather than lewd. A significant portion of proceeds goes to HIV/AIDS research. Arrive early; by noon the crowds around the shrine are extremely dense.