A £2MILLION conservation project to tackle problems caused by climate change at Corfe Castle has begun.

The project is the biggest one the castle has seen since the 1950s and will take three years to complete.

Across that time, specialist rope access teams will conserve the walls by removing vegetation and preventing future damage.

The work will be carried out on the nine towers, the keep and the eight-metre-high curtain wall and will see the teams suspended above the ground.

The castle is subject to regular structural condition surveys and while it is structurally stable now, there is concern about the impact of climate change.

In particular, the accelerating growth of vegetation such as valerian which grows its roots deep into the core of the walls.

Project manager Christina Newnham said this affects the castle at the two extremes of the weather.

“The real impact we saw was the drought in 2022 when the walls dried out and stones were regularly falling,” Christina said.

“The hot weather and heat dries out the mortar but it also kills off vegetation. Where plants have roots deep in the walls, as they die and shrink, the stones loosen, putting them at risk of falling. “Lime mortar needs moisture to be stable, as do the plants, and it was obvious after the first rain following the drought that the stones immediately stopped falling from the walls.”

Christina added: “We are using traditional techniques raking out the loose mortar and digging out deep tap roots from the invasive plants, re-pinning loose stones and repointing with fresh lime mortar as it would have been done hundreds of years ago.

“By sourcing aggregates from across Purbeck as the original castle builders did, we can create different colour mixes which allows the new mortar to blend in.”

One area the work will focus on is the east turret, where part of an arch was seen 30 years ago, which potentially was the site of the gateway where Parliamentary soldiers were given access to the castle during the Civil War.

The project is mostly funded, but a £100,000 fundraising campaign has been launched to support the work.

For more information, visit the National Trust website.