AN ICONIC Purbeck landmark is set to feature in the upcoming third series of BBC’s Hidden Treasures of the National Trust.

Corfe Castle, which was built after the Norman conquest in 1066, was destroyed in 1643 after it found itself on the front line of conflict between Parliament and King Charles I during the Civil War.

The ruins still stand today and are set to feature in episode four of the BBC show, airing on June 6.

The hugely popular series shines a light on the experts and volunteers who look after the properties and collections in the National Trust’s care and features four National Trust places in the south west.

Scheduled for 9pm on BBC Two and BBC iPlayer, the programme will explore the work going on behind the scenes to look after the incredible objects and properties in the charity’s care.

The series introduces viewers to the passionate staff, volunteers and external specialists who care for some of the 500 places in the Trust’s care, all narrated by actor and national treasure himself, Toby Jones.

Episode four focuses on the role of women ‘holding the fort’ while men were away fighting and includes the legacy of Lady Mary Bankes and her defence of Corfe Castle against parliamentarian troops during the Civil War.

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She had been left with her 11 children, servants and five soldiers while her husband Lord John Bankes, Attorney General to Charles I was fighting for the Royalist cause.

Lady Mary Bankes and a separate small group of defenders held the castle against the odds through two sieges.

A National Trust spokesperson said: “Though we believe she was not present at the castle during the siege of 1646 and when the castle was betrayed, her reputation for bravery and leadership has endured and her story continues to inspire and shape how the castle is remembered today.”

The episode also follows a recent excavation by archaeologists looking to find the long-lost sallyport – a gateway in the external wall which was opened by traitors to let the Parliamentary forces enter and take control of the castle.

A small archway in the east wall of the Inner Ward had been previously uncovered and matched the position and form of a potential sallyport.

Martin Papworth, National Trust Archaeologist for almost 40 years, began his National Trust career at Corfe Castle and wanted to uncover the mysterious arch on his last dig before retiring.

Martin said: “The sallyport is fundamental to the history of Corfe Castle, the capture of Corfe by the enemy troops tricking their way through this entrance, enabled Parliament to order its demolition – today’s much-loved ruin is the direct result of this action.

“Letters from the time describe Parliamentarians quickly getting control of the Inner Ward which made us suspect there was a sallyport high in the castle.

“The arch within the Inner Ward seemed an obvious place to explore”.

During the dig, a number of finds were made – fragments of lead frames and glass remnants from a Tudor window – probably from the Gloriette/ Queens Tower and 16th-century pottery shards including fragments from a bright green glazed earthenware bowl 55cm (22in) in diameter.

There was also painted plaster on the walls.

Viewers will find out if the team were able to unravel the enduring mystery or if it raises more questions than it answers.

The excavation was granted by Historic England as part of a major £2million, three-year conservation project to ensure the castle is protected for future generations.

Climate change is causing warmer and wetter winters encouraging more vegetation growth some of which can penetrate deep into the wall, loosening stones.

But in the summer droughts and dry weather dries out the lime mortar which, along with the vegetation dying off, loosens the stones of the castle walls.

A fundraising appeal is underway to complete the work and as part of this, rare permission has been granted by Historic England to build a platform high within the Keep.

Called the Kings’ View, the platform sits where the royal living quarters once were, providing exceptional views of the landscape and close ups of rare historic features.

Until recently, this part of the castle had been inaccessible to everyone except conservation teams on ropes. The Kings’ View will be open throughout 2025 only and can be accessed in two ways:

Guided tour and Kings’ View experience Lasting 90 minutes, a guided tour of the castle culminating with the Kings’ view experience (booking advised via website). Cost: £15.

The Kings’ View experience Lasting 30 minutes, visitors can access the viewing platform while on a usual visit to the castle (book on arrival). Cost £5.

All donations and funds raised from the Kings’ View will go directly towards conservation works.

Corfe Castle is open daily from 10am. For further information, visit: nationaltrust.org.uk/visit/dorset/corfe-castle