Valley of The Moon Vintage Festival 652 Po Box, Sonoma, CA95476 The valley of the Moon Vintage Festival has been celebrating the harvest of wine grapes in Sonoma since 1897. Yearly the…More event is held the last weekend of September. It not only provides a fun celebration for the community and visitors, but it also helps support local non-profit organizations. The celebration, held in the historic Sonoma Plaza, offers two days of fun filled events. Activities such as live music, a 5k walk/run, ameture wine competitions, blessing of the grapes and grape stomping competitions will keep locals and tourists alike entertained for the entire weekend.