The Wave-Gotik-Treffen is the world's largest festival for Gothic, darkwave, and alternative dark culture, held every Whitsun weekend (late May or early June) in Leipzig. Around 20,000 visitors from across Europe and beyond descend on the city wearing everything from Victorian mourning dress to post-industrial armour, making Leipzig's streets one of the most spectacular free spectacles in Germany for those few days.
The main stages run across multiple venues, from the Agra exhibition centre to historical spaces in and around the city. Beyond the concerts, there are markets, poetry readings, cemetery walks, and a famous Victorian picnic in Clara-Zetkin-Park where costumed attendees gather for photographs. Even if you are not a fan of the music, watching Leipzig respond to an influx of 20,000 elaborately dressed strangers is genuinely entertaining.