Dubbed Berrima Gaolbreak, the event is being organised by the Rotary Club of Berrima District to raise funds for essential community projects.

Club president Allen Cupitt said the response to an earlier call for volunteers had been good, but around 60 more helpers were still needed.

"We are expecting up to 3000 visitors to the three-day event and we need enough volunteers to make shift workloads manageable," he said.

Tours would run from 9am to 5pm, Saturday to Monday, with evening entertainment provided on Saturday and Sunday.

"Broadly, this means at least three shifts per day are needed for at least the first two days, with heavy demand expected on Australia Day itself," Mr Cupitt said.

He said the event would give volunteers a rare opportunity to see inside the landmark local gaol and would be of particular interest to those interested in the history of the region.

Volunteers would also have the satisfaction of knowing they were contributing to a worthy cause.Mr Cupitt said volunteers were also needed to help with the evening entertainment and those with Responsible Service of Alcohol cards would be highly regarded.

The Rotary Club has secured several prominent opera singers and performers, including Cheryl Barker, Michael Lewis, Nicole Youl, Richard Lane and Stephen Mould, for a concert on Sunday evening.

A bush dance will be held on the Saturday evening.Tickets to all evenings, including discounted tickets for gaol tours, are available at www.gaolbreak.org.au or from Destination Southern Highlands on 1300 657 559.

Volunteers interested in working on any or all of the three days should contact Wingecarribee Volunteer Centre, which I assisting the club with the search.Call the centre on 4869 4617 or email info@volwing.org.au for more details of positions available and the shifts required to be worked.

Alternatively drop into the centre at Queen Street, Moss Vale and pick up an expression of interest form.

The centre is open from 9.30am to 1pm Tuesday to Friday.