A group of teenage drinkers went on a wrecking spree inside Clitheroe Castle Museum, which is currently being renovated as part of a £3.2million heritage scheme.

The vandals started a fire and damaged a wall after buying six litres of cider form a nearby booths store, Blackburn magistrates were told.

Peter James Cryne, 18, of Riverside, Clitheroe, pleaded guilty to criminal damage - causing £750 to a wall. He was given a conditional discharge for 12 months and ordered to pay £500 compensation and £30 costs.

Catherine Allan, prosecuting, said Cryne and some of his friends had bought six litres of cider from Booths.

"It was wet and windy so they decided to climb into the Castle Museum to drink it," said Miss Allan. "They used their mobile phones to light the way to a second floor room."

Cryne and two others then attacked a wall, knocking off the plaster, ignoring the protests of one of their friends, she said.

"The friend tried to stop them but they continued for 15 minutes resulting in the wall being badly damaged," said Miss Allan. "The defendant and the man who tried to stop him left and when they returned the other two had started a fire.."

Miss Allan said a 15-year-old girl had been given a final warning for her part in the incident and an 18-year-old male had been given a caution on condition he paid £250 compensation.

Richard Prew, defending, said his client and his friends went into the museum because they couldn't find anything better to do.

"I don't know if that is a sad indictment of facilities in Clitheroe," said Mr Prew. He said the group had heard the museum was accessible and climbed in through a window.

"They initially sat there drinking and talking but as they got more drunk someone decided to cause damage to the wall and my client accepts that he joined in," said Mr Prew. "He accepts the historic nature of the building and that it is a positive for Clitheroe and he wants to apologise."

The new Clitheroe Castle Heritage Scheme will include an education suite, exhibition space, interactive displays, a cafe and shops and disabled access.

It is expected that the castle site will reopen in March 2009.