The National Trust has announced Lindisfarne Castle is set to close from November 2016 till April 2018 while it undergoes £3 million conservation works.
The castle, on Holy Island in Northumberland, is a Grade 1 listed building which overlooks the North Sea.
Due to its exposed location, the National Trust says it has been "ravaged" by the elements throughout its 460 year history and the large-scale project is essential to ensure that the building is conserved for the enjoyment of future generations.
The extensive works will focus on addressing damp issues and restoring the stonework, painting and windows.