The 150-year-old Shirley Windmill has just benefitted from a £45,000 refit after its sails were worn down by rot and marauding parakeets.

The historic mill survived the Blitz, several lightning strikes and threats of demolition but has recently come under threat from rose-ringed parakeets who like to sharpen their beaks on the sails.

The damage they inflicted was so bad, the council were forced to repair the expensive sails which can cost more than £10,000 each.

John Jackson, chairman of the Friends of Shirley Windmill, said for the past few months, specialist millwrights J. Hole have been hard at work fitting the new sails.

He said: “The mill will look splendid again with a complete set of new, freshly painted sails and shutters.”

To celebrate the refit, the Friends of Shirley windmill are organising a special open day from 12pm on May 9, which is also National Mills day.

Apart from the parakeets, the building suffered two air strikes during the Second World War but was miraculously left standing.

It had to be rebuilt in 1854 to replace the previous mill that burned down in a fire. It has also been struck numerous times by lightning.

The windmill, at the top of Postmill Close off Upper Shirley Road, is open to visitors over the summer every year and is one of only five open to the public in the whole of greater London.

A council spokesman said: “We are delighted to see this important heritage building restored to such a high standard and hope that the many visitors enjoy exploring the history and workings of one of only four mills open to the public in London.

"We are also grateful to the Friends of Shirley Windmill for ensuring this building is preserved and made accessible to the people of Croydon.”

The mill is open to the public on June 6, July 4, August 1, September 5 and 19 and October 3. Tours start at 1pm with the last one at 4pm.