Wacken Open Air (/ˈvɑːkən/, abbreviated as W:O:A) is a rock music festival, held annually since 1990 on the first weekend of August in the village of Wacken in Schleswig-Holstein, Germany. Almost all styles and subgenres of hard rock and metal are represented and hosted. It is now one of the largest heavy metal festivals in the world and one of the largest open-air festivals in Germany. Between 2011–2018, the number of attendees was around 85,000, 75,000 of whom were paying visitors. Due to the COVID-19 pandemic, there were no 2020 and 2021 editions of Wacken Open Air.