West Hollywood Halloween Costume Carnaval This is one of the largest Halloween street parties in the world, and there’s really no better place to be on October 31st. Sure, the crowd is huge (like, a half-million people huge) and a bit belligerent, but the amazing display of costumes and general merry-making spirit deem it at least a worthy stop, if not your main destination for the evening. There will be dancing, drinking and many impromptu costume contests. Even if you don’t plan on entering one, it’s best to still come dressed to the nines—no one likes a party pooper in jeans and a T-shirt. Find it along Santa Monica Boulevard, between Doheny Drive and La Cienega Boulevard.