Mains Castle dates from around 1450 and was first occupied in 1478 by Princess Euphemia Stewart and her new husband, David Lindsay, who was Provost of Glasgow.
The property fell into dilapidation 200 years later when it was fired at by the Claverhouse Dragoons, with cannonball marks still visible on the lower castle walls.
But the Victorians restored the East Kilbride castle in 1883, only for it to lose its roof in a 1922 storm, and be derelict until the 1970s.
It was at this stage the castle, which sits on land once thought to have been owned by Robert the Bruce, to undergo a painstaking eight-year restoration.
The walls range from six to ten-feet deep, with accommodation configured over five storeys.
Mains Castle’s spiral turnpike staircase - which rises through the full height of the building - was cunningly designed in a clockwise direction to give a right-handed swordsman the advantage over an intruder trying to fight his way up.
The ground and first floors are enclosed by a stone barrel vault with the ground floor housing a banqueting hall overlooked by the minstrels’ gallery on the floor above.
An original guardroom has been converted into a cloakroom/WC complete with stone clad cistern and copper wash basin.
The flagstone-floored Great Hall serves as the main kitchen and living room. The rough hewn stone walls and solid oak beams make this a wonderfully atmospheric space.
On the third floor of the A-Listed property is a master bedroom suite, a second bedroom and a toilet, the fourth floor has an additional kitchen along with a third bedroom and bathroom.
The 40ft high castle, set in almost three acres of parkland and overlooking James Hamilton Heritage Loch, has now been put on the market with Savills for offers over £495,000.
It is the oldest inhabited property in East Kilbride, which is nine miles from Glasgow city centre, 16 miles from Glasgow Airport and 40 miles from Edinburgh Airport.
Peter Gillespie, from Savills, said: “Mains Castle is the real thing - a ‘proper’ fairytale castle that has been brilliantly and sympathetically restored without losing any of its imposing and powerful ambiance.
“For anyone dubious about modern living in a castle, this property proves how it can be done.
“In its parkland setting and with an easy commute into central Glasgow, Mains Castle is well worth consideration by a buyer seeking their very own slice of Scottish history.”