People can enjoy free access to more than 80 venues across County Durham next month, as part of England’s largest festival of history and culture.

Heritage Open Days celebrates its 25th anniversary this year and, to mark the occasion, the event has been extended from its usual long weekend to ten consecutive days between Friday 13 to Sunday 22 September.

The annual celebration of the country’s fantastic architecture, parks, gardens and culture, offers free access to properties that may usually be closed to the public or may normally charge an admission fee.

From stone masonry demonstrations to cheesemaking tours, County Durham’s Heritage Open Days programme is cram packed with a wide range of tours, events and activities designed to bring local history and culture to life.

Cllr Joy Allen, Cabinet member for transformation, culture and tourism, said: “Heritage Open Days is a great way for people to learn about County Durham’s past and families can make the most of these events for a great free day out.

“As well as the usual fantastic range of activities, a host of new events and venues are taking place in this 25th celebratory year, which is guaranteed to be the biggest and best yet. There’s loads to see and do across the ten days including many opportunities to participate, from short visits to full days out.”

Highlights of the festival include an opportunity to visit Consett’s Allensford Blast Furnace, the earliest surviving ore-roasting kiln in Britain, cheese making in Butterknowle,Teesdale and a walk-through art installation, featuring lights and inflatables, at Peterlee’s Apollo Pavilion.

In Barnard Castle people can find out about the town’s grade I listed Market Cross and its past life as a fire station, town hall, court house and sales venue, whilst visitors to the Ankers House Museum, in Chester-le-Street, can view artefacts from the market town’s Roman, Anglo-Saxon and Medieval past, as well as a facsimile of the Lindisfarne Gospels.

A range of free guided tours are on offer too, from exploring the woodland on a family trail at Derwentcote Steel Furnace to discovering the hidden landscape of Castle Eden Dene National Nature Reserve. Another guided walk will call at Durham City locations associated with crimes and their punishment, from the Middle Ages to the present day, and will be complemented by a look at 400 years of crime and punishment records at Durham County Records Office, telling stories of dastardly deeds and hard times.

Other events will give access to painting and art collections, and hidden architectural treasures. People will receive a fresh view of many of the county’s churches, castles and cathedral, and can explore outdoor spaces such as the restored Old Durham Gardens and a poetry trail through the beautiful North End allotments. There’s also a chance to learn about significant historical remains such as those of Beaurepaire Manor House and Binchester Roman Fort.

Railway enthusiasts can ride on the Thorpe Light Railway, enjoy a talk about the progress made preserving the Stockton and Darlington Railway, take a historical walk along a section of its original track bed, and see the sights of the Locomotion museum in Shildon on its special themed tours.

All activities are free, but booking is required for some tours and activities.

For full event details, including booking details, pick up a brochure from a council Customer Access Point or library, or visit www.durham.gov.uk/heritageopendays.

To coincide with Heritage Open Days, Bishop Auckland Heritage Action Zone is holding its first History and Heritage Festival with walks, talks, workshops, displays and a radio programme and film screening. More information can be found at www.durham.gov.uk/haz