This year's Halloween Massive event will be at Park Central Hotel in Union Square. 15th Annual Halloween Massive “Vixens & Villains” is back for a serious nocturnal party delight for party fiends who are ready to let their inhibitions loose on 3 dance floors and massive ballroom. The first dance floor features Top 40, EDM, and other club hits. The second dance floor features hits from the 80s, 90s, and 2000s. The third area is for those that love salsa and merengue. This is one of the Halloween parties in SF with a costume contest.