Westbury White Horse cleaning under way in Wiltshire
A team of volunteer steam cleaners are said to be making an "unbelievable" difference to a Wiltshire hillfigure.
The 175ft (53m) Westbury White Horse, which has greyed and deteriorated, is being refurbished in time for the Queen's Diamond Jubilee next month.
Twelve volunteers have spent the day on the end of a rope scrubbing the horse which is carved onto a steep hillside.
Steve Carrington, who has organised the work, said: "It really is quite amazing the difference it makes."
The project is being led by the Westbury Rotary Club and is the first restoration of the White Horse since 2006.
Rotarian Mr Carrington said the contrast between a scrubbed area and an untouched area was like "night and day".
"I've got a guy who is cleaning a section and where he is stood is chalky white and around him is almost black," he said.
Local residents and the rotary club are undertaking the work which includes a team of abseilers doing the scrubbing and others marshalling the area.
The volunteers are working from 08:30 BST to 18:00 BST on both Saturday and Sunday and are expected to do the same for the next two weekends.
Once clean, the hillfigure, which is maintained by English Heritage, will be primed before having two coats of special paint applied.
The horse is thought to have originally been carved into the hillside in 878 AD to commemorate King Alfred's victory over the Danes at the Battle of Ethandune.
A coat of cement was given to it in 1993 to halt its erosion and then it was painted six years ago.
As part of Westbury's Jubilee celebrations, the town council is planning to illuminate the carving with searchlights.