Sir Ian McKellen is to mark turning 80 next year by presenting a solo show on 80 different stages across the UK.
The tour will take the Lord of the Rings star to theatres with which he has personal connections, as well as some he has never performed at before.
Profits from the show, described as "a mixture of anecdote and acting", will benefit causes specific to each venue.
"The show starts with Gandalf and will probably end with an invitation to act with me on stage," the actor revealed.
"Growing up in Lancashire, I was grateful to those companies who toured beyond London," he said in a statement.
"I've always enjoyed repaying that debt by touring up and down the country myself."
Ian McKellen On Stage - a version of the one-man show he presented at London's Park Theatre last year - will kick off at Sir Ian's local arts centre on the Isle of Dogs on 25 January.
The nine months that follow will take in two of the National Theatre's stages, two more in Stratford-upon-Avon and four dates at the Edinburgh Festival.
The Old Vic, the Young Vic and the Bristol Old Vic will also receive visits, as will venues in Jersey, Orkney, Wales and Northern Ireland.
The 79-year-old, who turns 80 on 25 May, promised to be "upright and audible" by the time his epic tour comes to a close in London on 15 September.
"It's not a farewell tour," the actor and campaigner told the London Evening Standard. "It's more like 'Oh, hello again!'"
Sir Ian, who can be seen on BBC One on this week's edition of The Graham Norton Show, said the tour would be "quite emotional", adding: "It'll keep me on my toes."
Known to millions as Gandalf in the Lord of the Rings and Hobbit films, Sir Ian is an Oscar-nominated star of stage, screen - and pantomime.
Seen treading the boards this year as Shakespeare's King Lear, his upcoming roles include Gus the Theatre Cat in a live action film version of hit musical Cats.
A full list of venues he'll be appearing at next year can be seen on the show's official website.