An estimated 100,000 jubilant supporters gathered at the Canaletes fountain on Las Ramblas soon after the team beat defending champion Manchester United 2 - 0 in Rome on Wednesday .
Las Ramblas is the traditional site for celebrating the club 's wins .
An estimated 100,000 jubilant supporters gathered at the Canaletes fountain on Las Ramblas , the traditional site for celebrating the club 's wins , soon after the team beat defending champion Manchester United 2 - 0 in Rome on Wednesday .