Wacken Open Air (W:O:A) is a popular German music festival focusing on various forms of extreme metal and heavy metal. It takes place annually in the small town of Wacken in Schleswig-Holstein, northern Germany. With 70,000 festival visitors, and including personnel a total of over 72,000 attendees in 2007, it attracts all kinds of metal music fans, such as fans of black metal, death metal, power metal, thrash metal, gothic metal and also folk metal, from around the world.

The festival was first held in 1990 as a small event for local German bands. By 1998 the event had become the major festival on the European metal calendar and one of the most important in the world and included over 70 bands from all over Europe, North America and Australia. W:O:A is usually held at the beginning of August and lasts three days, during which the festival-goers camp on several large camping grounds surrounding the actual festival area. The 70 or more bands perform across four separate stages over the course of the event.

Wacken Open Air (简称WOA)是德国非常受欢迎的音乐节，以有大量不同风格的极端金属和重金属乐队的参与著称。音乐节每年在德国北部Schleswig-Holstein的Wacken小镇举行。2007年，有70000人次参与，包括乐队、工作人员等等共有超过72,000参与这个盛会。吸引来自全世界各地的各类型的金属迷，例如黑金、死金、能力金属、鞭笞金属、歌特金属以及民谣金属等。

该音乐节的在1990年首次举行，当时只作为德国当地乐队的小聚会。1998年后，该聚会变成了欧洲金属一年一度的大型音乐节，也是世界上最重要的音乐节之一，包括来自欧洲、北美以及澳大利亚等国逾70支乐队参与。WOA通常在七月底八月初的最后三天举行，来参与音乐节的歌迷们可以扎营在环绕音乐节区域的几个大型的帐篷里。整个音乐节会有超过70支乐队分别在4个不同的舞台表演。

到目前Wacken Open Air属于全球最大的摇滚音乐节，一年一度在德国北部小镇Wacken举行，时长一般为三天，在每年的7月至8月的某三天，演出形式为露天表演；wacken音乐节不同于其他形式的摇滚音乐节，wacken是历史上真正意义的金属音乐节；每次音乐节期间有夜晚的篝火，点燃整个小镇，夜里有乐队演出，有彻夜狂欢的歌迷，帐篷随处可见。是真正意义上的音乐和快乐的融合。

中国的摇滚乐手到至今只有崔健和杭盖乐队受邀参加过

值得一提的是，在中国教育出版社出版的英语教材，初中三年级下册中提到了open air由此可见open air的地位及影响。