What is the name of the annual heavy metal festival in Wacken, Germany?

What is the name of the annual heavy metal festival in Wacken, Germany? It is called Wacken Open Air.

Usually abbreviated as W:O:A, Wacken Open Air is held in the village of Wacken in Schleswig-Holstein, northern Germany. The festival began in 1990 and traditionally takes place around the first weekend of August, combining large-scale concerts with camping and a broad range of metal-related attractions.

The festival grew from a small open-air concert into one of the world's best-known heavy metal events. Its site includes major stages, smaller performance areas, food and merchandise stalls, and themed spaces such as the medieval-style Wackinger Village.

Download Festival, Bloodstock and Hellfest are also major rock or metal festivals, but they are not the annual event named after Wacken. Wacken Open Air is distinctive because the place name is part of the festival's official title and identity.