In 1954 the roof of Buchanan Castle came off. Not by accident, and not because of war damage. The Duke of Montrose's family had moved out in 1925, the building had served as a military hospital during the Second World War and briefly as the Army School of Education after it, and now the property carried a tax liability that no one wanted to pay. Removing the roof made the structure legally a ruin, and a ruin is taxed differently from a house. So down it came. Today, a mile west of the village of Drymen, the great Scottish baronial walls of Buchanan Castle still stand at full height inside a perimeter fence, slowly being absorbed by the trees that have moved in through the empty window-frames.
The castle you see today is not the original Buchanan seat. That building, Buchanan Auld House, stood half a mile to the northwest. It had been substantially rebuilt around 1724, altered by John Adam in 1751, and considerably enlarged in 1789 by William Playfair into a grand mansion with a principal front close to three hundred feet long, comparable in scale to Petworth House in Sussex. Then in December 1852, while the family were away celebrating Christmas, the housekeeper - according to the story handed down - drank too much, fell asleep, and woke to find the entire house in flames. Many valuable items were lost. The 4th Duke of Montrose commissioned the architect William Burn to design a replacement, and Buchanan Castle was built between 1852 and 1858 on a new site nearby, a Scots baronial pile in the high Victorian fashion.
The land had been Buchanan country since at least 1231, the family seat of the chiefs whose clan name the area carries to this day. By the late seventeenth century, however, the direct chiefly line had failed - the 22nd Chief, John Buchanan, inherited significant debt and watched the estate sold off piece by piece to satisfy creditors. The 3rd Marquess of Montrose, of Clan Graham, bought the property, and his son became Duke of Montrose in 1707. Buchanan Auld House was deemed a more fitting dwelling than the family's older seat at Mugdock Castle, and so the Grahams moved their centre of operations to Drymen. The Buchanan name stayed attached to the place. The clan that had given it that name was effectively gone.
William Burn was one of the most successful country-house architects of nineteenth-century Britain, and Buchanan Castle was a confident exercise in the style he had helped popularise: turrets, crow-stepped gables, tall chimney stacks, ornamental machicolations that suggested medieval defensive lineage without ever pretending to military purpose. The Montrose family used it as their principal seat for sixty-seven years. They moved out in 1925, the great house already too expensive to run, the world that had built it dissolving. During the war, the building was requisitioned as a military hospital and then handed to the Army School of Education. By 1954 it had no peacetime function and no economic case. The roof came off, and the slow decline began.
Today, Buchanan Castle is a Category B listed building, sits on the Buildings at Risk Register for Scotland, and has been a ruin longer than it was ever inhabited. The walls remain intact at their full height and are considered structurally sound. A perimeter fence keeps explorers out, and a residential development has filled in some of the old castle gardens. Inside the shell, ash and sycamore have rooted in the floors, sending branches through what were once formal staterooms. The grounds were dropped from Scotland's Inventory of Gardens and Designed Landscapes in 2016, the formal park having softened back into ordinary woodland. Officially, the castle is still the seat of Clan Graham. Functionally, it is a beautiful ruin half a mile from the village green, taken over by the forest at its own slow speed.
Located 1 mile west of Drymen at 56.07N, 4.47W. From altitude, Buchanan Castle appears as a roofless rectangular shell surrounded by woodland, with the residential development visible in former parkland to the south. Best viewed at 2,000-3,000 ft AGL in clear conditions. Loch Lomond is about 3 nm to the west; Ben Lomond visible to the north-northwest. Drymen village sits to the east. Nearest airports: Glasgow International (EGPF) ~13 nm south, Glasgow Prestwick (EGPK) ~28 nm south-southwest, Cumbernauld (EGPG) ~16 nm east-southeast. Class D Glasgow CTR begins to the south, check airspace before low flight.