Vandals struck at a Grade II listed building in Fleetwood which is part of the town’s maritime heritage.
The yobs attempted to torch one of the benches inside the Lower Lighthouse, some time between Sunday night and Monday morning.
It occurred just when the building, co-designed by famous architect Decimus Burton, was in the process of being spruced up by Wyre Council, which owns the building.
Residents, business folk and heritage figures in Fleetwood were dismayed by the incident.
Margaret Daniels, chairman of Fleetwood Civic Society, said: “We need to respect and cherish these buildings, not vandalise them, they make Fleetwood special.”
Craig McOmish, who runs the nearby Fleetwood Beach Kiosk, saiD: “ The Lower Lighthouse is an iconic building in Fleetwood.
He posted: “Ir is very disappointing that these people have such little respect for their town.
“It’s great to see Lower Lighthouse getting a well overdue lick of paint, but the hard work put in during the last few days has been ruined due to mindless vandalism.
“One of the benches inside has been scorched! It’s already had three coats of staining which will have to be taken back and started again.”
“Such a shame; the guys doing the work are gents who take pride in their work.”
A Wyre Council spokesman said there had been an attempt to burn of the benches inside the lighthouse’s ground level colonnade shelters.
The spokesman added: “It is very unfortunately but the work will continue.”
The Lower Lighthouse was designed in 1839 by Burton and Capt HM Denham, in neoclassical style.
Among the many people commenting on Facebook was Gerard McCaul, who said: “Things have gone from one extreme to another, don’t these idiots realise this is their town?”