Recorded over 6 months in 1991 in Berlin and Dublin, Achtung Baby was U2's seventh studio album. It was produced by Daniel Lanois, Brian Eno and Steve Lillywhite and mixed and engineered by Flood. Led by "The Fly", Achtung Baby spawned four more huge hit singles, "Mysterious Ways", "One", "Even Better Than The Real Thing" and "Who's Gonna Ride Your Wild Horses". Heralded by Rolling Stone's Robert Hilburn as "U2's daring descent into darkness", the album was awarded the Grammy for Best Rock Performance and became one of the most acclaimed rock records of the nineties and of U2's career. As Bono said at the time, it was "the sound of four men chopping down the Joshua Tree".