Princess Anne opens revamped Monmouth Shire Hall
The Princess Royal attended the official reopening of the newly restored Shire Hall in Monmouth later.
The Grade I listed building, which dates back to 1724, has undergone a £4.5m restoration.
The work included restoring a courtroom where leading members of the chartist movement were condemned to death for high treason in 1840.
The princess toured the building as part of celebrations which will include a Spitfire flypast.
Facilities at the site include an audio-visual guide of the hall's courtroom recreating the trial of John Frost, leader of the Chartist uprising in Newport of 1839.
He and other members of the movement were held in the cells of the building while they waited for the verdict.
Their sentence of capital punishment was later commuted to transportation for life.
The refurbishment of the hall, which began in September 2008, was funded with £3.2m from the Heritage Lottery Fund (HLF) and more than £1m from Monmouthshire council.
The princess unveiled a plaque commemorating the reopening of Shire Hall.
Peter Fox, leader of Monmouthshire County Council said: "I'm so proud that we can open this beautiful building and that it is now accessible for everyone to use."
Dan Clayton Jones, chair of the HLF committee for Wales, said: "This award to Monmouthshire County Council has helped them to conserve one of the county's most significant and historic buildings, and bring to life its rich heritage."