DragonCon is a yearly convention held in Atlanta that caters to fans of science fiction, fantasy, comic books, anime, literature and technology.
I've found it to be one of the most diverse gatherings of people on the planet. Attendees traverse the country, and the world for this event.
One thing remains constant throughout these types of conventions - and that's a love of cosplay and an opportunity to let go and be yourself for a weekend. Though, wearing a mask certainly doesn't seem to hurt.