Welwyn Garden City's Barn Theatre is inviting the public to explore its historic building during a free open day.

As part of its Heritage Open Days, the theatre will offer behind-the-scenes tours of its performance spaces and backstage areas on Sunday, September 15.

Staff will be on hand to discuss what makes a successful production, with costumes, props, directing, set building, and sound and lighting all covered.

Visitors will get to witness rehearsals for upcoming shows.

The theatre, which stages an average of 12 productions per year, occupies a historic building dating back to the 19th century - while the original barn building dates to 1598The theatre, which stages an average of 12 productions per year, occupies a historic building dating back to the 19th century. The original barn building, parts of which can still be seen, dates to 1598 (Image: Supplied)

Ian Major, chair of the Barn, said: "We're a very inclusive club that welcomes all those people, young and old, interested in the theatre.

"We’re always looking for new members to join us, whether that’s in an acting role, or by joining our backstage, front of house, or creative teams.

"Many of our members simply enjoy the social aspects of the theatre, including special club nights and social events in the Club Room Bar - there’s lots of ways people can get involved."

Established in 1932, The Barn Theatre occupies a building dating back to 1830.

The original barn building, parts of which can still be seen, was constructed all the way back in 1598.