The 780 year old building, Cumbria Rose Castle, is for sale for £2.5 million.
It was the seat of the Bishop of Carlisle from 1233 until 2009.
The Grade I listed castle sits upon 193 acres of land and could become a school, a wedding venue, or a private home according to the estate agents Savills/BNPS.
The castle features 16 bedrooms, six bathrooms and a further four loo rooms, state drawing and dining rooms, a private drawing room, sitting room, family room, two kitchens, a bishop's study, a secretary's room, a number of utility rooms as well as larders and its own chapel.
The chapel even has stained glass windows that are thought to have come from Lambeth Palace.
John Coleman from Savills, the estate agent, told The Mirror: "It's one of the most significant houses in Cumbria and the link to the Church makes it more fascinating to the market, it's attracting a lot of attention.
"The gardens are very special, beautifully looked after and there is farmland and additional accommodation which could be developed or used for staffing for the big house."
He continued: "The history and the scale of the property is attracting interest and it's exceptional value for a property of this size.
"It is occupiable now but it is dated so we anticipate the next owner to invest to modernise it.
"The property has great grounds surrounding it. It runs down to the river and to the north the land rises up and there is a lot of land for sale with the house so people can have as much privacy as possible."
The surrounded area is well-known for its grassy hills overlooking the Caldew Valley.
It was first used as a Bishop's residence in 1233 but was later burnt down, until 1355 when a bishop set about building a castle with a tower at each corner.
In 2009 the Church decided it was too costly to staff the building.
The property is being sold in three separate lots; the main house and formal gardens, as well as three cottages, a farmhouse and farm buildings and about 61 acres of land.
