Prince Charles and Camilla Parker Bowles have changed the venue for their forthcoming wedding on 8 April.
The new venue will allow the public to see the couple arrive and leave
The pair were set to hold a civil ceremony at Windsor Castle but Clarence House has now confirmed they will marry at the Guildhall in Windsor.
The couple made the decision on the grounds that licensing the royal castle would cause too much disruption.
The wedding will be followed by a prayer service led by the Archbishop of Canterbury at St George's chapel.
Clarence House says the new venue will allow the public to see the newlyweds arrive and leave.
Mrs Parker Bowles has chosen Robinson Valentine to design her wedding outfit and Philip Treacy to design her hat for the ceremony.
Once married, she will take the title of HRH Duchess of Cornwall and then Princess Consort if Charles becomes king.
A Daily Telegraph poll of 1,313 people suggests two-thirds of Britons support the couple's decision to marry.
But only 40% think Mrs Parker Bowles should become Princess Consort as planned.
Some 47% believe she should have no title, while 7% think she should become queen.
The poll also suggested that the majority of Britons would prefer the monarchy to miss a generation, with the Queen handing the throne to her grandson Prince William, 22, on her death or abdication.
Mrs Parker Bowles, 57, said the prince went down on one knee to propose and added: "I'm just coming down to earth."
Charles, 56, said he and his wife-to-be were "absolutely delighted".