Old Dalquharran Castle and Dalquharran Castle stand within sight of each other deep in the beautiful Ayshirer countryside close to Dailly.
The original castle dates from the 15th Century with the other built around 300 years later for its owner, Thomas Kennedy of Dunure, a Tory MP and lawyer.
Kennedy of Dunure had married Robert Adam's sister, with the round tower and central staircase inspired by the design of Culzean.
The new castle is a Grade A listed building but has been abandoned for almost 50 years. Both properties now lie in ruins.
The castles are being sold for £800,000 with the same price getting you a two-bedroom flat in Islington, Hoxton or Marleybone, according to current estate agent particulars.
Several multi-million pound schemes for Dalquharran have been put forward in recent years, including one for a hotel, 18-golf course and new homes in the grounds.
Included in the sale of the castles is around 160 acres of farmland and another 72 acres of Woodland.
The new castle was sold in the 1930s to Lord Salvesen and leased the castle to the Scottish Youth Hostel Association from 1936 to 1939.
It was occupied by Langside School for the Deaf during the Second World War to take its pupils evacuated from Glasgow.
During the war, the estate were sold to John Stewart, who occupied the castle with his family and farmed the estate, but it was eventually abandoned given the cost of keeping the castle going.
The lead roof was removed in 1967 with the building redundant since then.
The sale is being managed by Rettie and Co.