Rock in Rio is Brazil's marquee music festival and one of the biggest in the world. Thirty years after its first event in 1985, Rock in Rio 2015 was the sixth edition of the massive festival in its home country. The fest sees an estimated 85,000 attendees per day, taking over a venue aptly named "Cidade do Rock" (City of Rock) in Rio de Janeiro. 

Developed in preparation for the 2016 Summer Olympics, the new Cidade do Rock housed far and away the most extravagant Rock in Rio yet. We're hard-pressed to think of a festival where Metallica and Katy Perry can headline opposite weekends, or Mastodon and Rihanna can walk along the same stage. You see, Brazilians have some of the most eclectic taste in music, where the same crowds can be massive fans of both Elton John and Slipknot or welcome The Hollywood Vampires – a supergroup consisting of Johnny Depp, Alice Cooper,  Aerosmith's Joe Perry and Guns N' Roses' Duff McKagan – with open arms, alongside classic Brazilian acts like Paralamas do Sucesso and Cidade Negra,spliced in with DJs and break dancing troupes.

Not enough? Each of Rock in Rio's six days (spread out over two weekends) features a wedding, ends with a gigantic fireworks display along the waterfront, and sees colorful people from all walks of life enjoying themselves rain or shine. You gotta see it to believe it. Here are some of the best moments from this festival and its culture that are truly one of a kind.