The King and Queen will be visiting Theatr Brycheiniog in Brecon tomorrow (Thursday, July 20).
The royal couple will meet with members of the community and celebrate local volunteers and public service sector at the theatre.
Upon arrival the royal couple will go to a field next to the theatre, where they will see elements of Brecknock Agricultural Society's annual show.
King Charles and Queen Camilla will also have the opportunity to speak to local food and drink producers, as well as representatives from Black Mountains College.
Aberhonddu Male Voice Choir will be singing in the background as they are meeting representatives at various stalls.
King Charles will then be invited to add some soil to an oak sapling that will later be replanted in the Brecon County Showground.
Following this, the King and Queen will be invited to join a reception for 100 guests.
The guests will include Welsh Coronation Champions, members of the Brecon Mountain Rescue Team, and representatives from the Brecon Women’s festival and of the local health service.
Music during the reception will be provided by the Swing Strings Trio, a group of three top Welsh Jazz musicians who are regular performers at the annual Brecon Jazz Festival, which celebrates its 40th anniversary in August.
King Charles and Queen Camilla will enjoy performances by Theatr Brycheiniog’s Lunchtime Uplift Choir and the Alive & Kickin’ Community Choir Brecon.
Their Majesties will then be invited to help unveil a plaque to mark their visit.
The King opened the theatre as Prince of Wales a quarter of a century ago in 1997.
Follow our liveblog tomorrow for coverage of this historic royal visit.