Cher is coming out retirement to play a series of sensational Las Vegas shows.The 61-year-old singer - who claimed she would never perform live again after her 2005 'Farewell Tour' - has signed a deal reportedly worth more than £100 million for a three-year residency at Caesars Palace hotel.Cher said: "It is going to be a visually unbelievable show with brilliant choreography. Our set moves down from the ceiling, in from the sides, up from the floor. We have screens in the foreground, the centre and the back. We can change a city into a forest in two seconds. You'll see a different stage for every song."The 'Believe' star is expected to perform four shows a week at the venue's 4,100 seat Colosseum starting from May 6.She will then take a short break before returning in August for another two-month stint.Cher's last tour began in June 2002 to promote her 'Living Proof' LP. It was later renamed the 'Farewell Tour', and eventually went on so long it became dubbed 'The Never Can Say Goodbye Tour'.The singer performed across North America, Europe, Australia and New Zealand, and earned Cher in excess of £95 million.