A 53-metre-long safety deck high above the Kent cathedral's nave has been built for a conservation team to work from and to catch any dislodged stone and plaster.
The 33-tonne platform - the size of three tennis courts - sits 52ft (16m) above the nave floor, supported by aluminium beams and 1.9km of scaffold tubes.
Its construction marks the start of physical works of a £24.7 million development known as the Canterbury Journey, funded by the Heritage Lottery Fund and donations from private and charitable sources.
Over the next five years, the cathedral's West Towers, the leaking nave roof, and the cathedral main entrance, the Christ Church Gate, will be repaired and restored.
In addition, the Precincts will be landscaped to create better access and to improve their appearance, and a new welcome centre is also being built.
The huge deck has given cathedral conservators the type of access to stained glass and the interior vaulting of the nave roof not seen for hundreds of years.
Mark Hosea, the project director of the Canterbury Journey, said: "The deck has become quite the talking point for visitors and those working in the cathedral.
"It has been amazing watching it being built and the height has afforded stunning new views of the building.
"Cathedral conservators have not had this extent of access to stained glass and the interior vaulting of the nave roof for hundreds of years, and I know that everyone involved is feeling a real sense that history is being made."