Police are appealing for witnesses after two windows were broken at Market Deeping’s 175-year-old town hall.
The incident is believed to have taken place on the weekend of July 26 and 27.
Mayor of Market Deeping Coun Roy Stephenson said: “Vandalism is always unpleaseant when it happens but to an old public building such as the Town Hall it is particularly distressing.
“Unfortunately the cost of mending it will be on the shoulders of the ratepayers.
“Whoever was responsible has also let down all of our law-abiding citizens of all ages.”
Anyone with information please call police on 101 or Crimestoppers, anonymously, on 0800 555 111, stating incident 136 of August 6.