Wacken Open Air (W:O:A) is a summer open-air heavy metal music festival. It takes place annually in the small village of Wacken in Schleswig-Holstein, northern Germany. With 80,000 festival visitors, and including personnel a total of roughly 86,000 attendees in 2011, it attracts various kinds of metal music fans.The festival was first held in 1990 as a small event for local German bands. W:O:A is usually held at the beginning of August and lasts three days.