BERLIN — Fans hoping to catch a glimpse of U2’s free concert celebrating 20 years since the fall of the Berlin Wall will have to “scale these city walls” after organizers threw up a massive barrier to block the view for those without tickets.

The move has triggered outrage from Berliners, who see the irony in building walls around a concert dedicated to the wall that has come down.

Music network MTV, which organized Thursday’s concert in front of the Brandenburg Gate, did not respond to requests for comment.

Some 10,000 tickets were made available online for the Irish rockers’ free show — and they were snapped up in just three hours.

The Berlin Wall fell Nov. 9, 1989, ending almost 30 years of east-west Cold War division.