Explore Brentwood’s history at an open day this weekend.

Essex Record Office in Chelmsford will be opening its doors to mark a free open day on Saturday and will include guided tours to mark its 75th anniversary.

The event is part of the national Heritage Open Days to show residents historical buildings for free.

Archivists Sarah Ensor and Allyson Lewis will be on hand to talk about some of the borough’s earliest maps made of parchment, and have stayed in a relatively good condition, and how they have been preserved.

The maps from the early 1700s and 1900s show South Weald as Brentwood was not a parish at the time.

The records office includes 1,000 years’ worth of the county’s history collected since it opened in 1938. The council employed a county archivist, Frederick Emmison, and were only the third authority to do this.

A selection of preserved documents will be available to view on the day, which will include tours, a chance to see the archived films, a talk and an anniversary cake.

County Cllr John Jowers, cabinet member for libraries, communities and planning, said: “Essex County Council is extremely proud of its achievement in founding and maintaining the Essex Record Office over the last 75 years, preserving our county’s past and making historic records available for public use.

“The ERO open day is the ideal opportunity to explore this treasure trove of fascinating material about our county’s past.”