By Carrie Sanderson July 14, 2026

Clan Colquhoun have always had great influence over their territory, and managed to increase their power and reputation with their collection of grand homes. We find that exploring a clan’s castles is one of the best ways to dive into their history, so come along with us to walk in the footsteps of the mighty Clan Colquhoun! 

Discover the Castles of Clan Colquhoun

Dunglass Castle

Perched on a rock overlooking the River Clyde near the village of Kilpatrick, stand the remains of Dunglass Castle, which long served as Clan Colquhoun’s ancestral seat. 

Dunglass is thought to have been built in 1380, with its location meaning it was no doubt highly strategically important for the Colquhouns. The clan would have been able to observe the river easily, monitoring access along this vital route from above, representing their power in the region. 

Dunglass served as a fittingly impressive home for one of the most influential members of the family in the 15th century, with Sir John Colquhoun, who served as Controller of the Royal Household, living in the castle from around 1439 to 1478. 

Dunglass Castle by Lairich Rig Dunglass Castle by Lairich Rig

Like most influential clan castles of the era, Dunglass experienced periods of turmoil and conflict. In the late 16th century, it was attacked by Lord Fleming’s forces on several occasions. Though the castle survived these attacks, its fortunes began to decline, and by the 18th century, it had fallen into ruin, with the Commissioners of the Supply ordering in 1735 that its stone be taken and used to repair a nearby quay. 

Surprisingly, this was not the end for Dunglass, and in 1812, it was purchased by Andrew Buchanan of Auchentorlie, who began to use it as a home once again. In 1893, the graphic artist Talwin Morris took over the lease, and remodelled the interior, refreshing the castle for a new era. 

Dunglass Castle Dunglass Castle drawn by F.A. Pernot

In 1899, Dunglass was leased to Charles MacDonald, the brother of renowned artists Margaret and Frances MacDonald. Margaret was married to the iconic architect Charles Rennie Mackintosh, and the pair set about making their own renovations, including a white room which Mackintosh later recreated in his masterpiece, Hill House. 

Today, only fragments of the original castle remain; a section of a boundary wall reaching around 7 metres high, a small conical dovecot, some corbels, and what appears to have been a pigeon house from the 17th century.  Despite its condition, Dunglass Castle remains a significant landmark in Scottish design and Clan Colquhoun’s history, exemplifying the great power they held over their much sought-after territories. 

Rossdhu House

Our next Colquhoun Castle also served a long period as the clan’s stronghold, and still maintains links with the Clan Colquhoun International Society to this day.

Stood by the scenic waters of Loch Lomond, you can find the stunning Rossdhu House. The name is thought to have derived from the Gaelic ‘Ros Dubh’, meaning ‘black headland’ or ‘black promontory,’ a fitting reference to the house’s wooded surroundings. 

The present day Rossdhu house was built in 1773 for Sir James Colquhoun, to replace the earlier medieval castle which had stood on the estate since the 15th century. Certain elements of the original castle have been maintained, most notably, the drawing room tables, which supposedly hold a fascinating place in royal history! Legend has it that Mary Queen of Scots once wrote a famous letter to her husband, Lord Bothwell, while seated at one of them. 

Rossdhu House by George Rankin Rossdhu House by George Rankin

Rossdhu remained the Colquhoun family home until 1993, when the Lyle Anderson Company transformed the estate into the prestigious Loch Lomond Golf Club. Today, Rossdu serves as a clubhouse, providing 43 luxury suites, a reception area, library, drawing room, dining room, and bar for members from over 32 countries. It boasts beautiful wood panelled interiors, roaring open fires, and stunning antique furniture, creating an opulent yet comfortable atmosphere. Members can also enjoy a number of outdoor pursuits, taking advantage of the scenic countryside to fish, play golf, and take boats out on the water.

While Rossdhu House is not generally open to the public, the Clan Colquhoun International Society occasionally arranges visits for society members. Another great reason to consider joining! 

Bannachra Castle

Our final Colquhoun site for today is the grand Bannachra Castle, which now stands in ruins, overlooking the Fruin water.

The lands of Bannachra were held by the Galbraith family in the 15th century, before being sold to Clan Colquhoun in 1523. It is likely that the castle was built shortly after, strategically positioned to have a sweeping view over the surrounding countryside. 

Bannachra is arguably most infamous for the dramatic assassination of Sir Humphrey Colquhoun of Luss in 1592. The details of the story have been lost to history, but it is thought that the chief was chased to the castle by members of the rival Clan MacFarlane. He reached home, but sadly instead of finding safety within its walls, he found betrayal. 

A servant guided Sir Humphrey up a narrow and winding staircase, before deliberately lighting a lantern, revealing a silhouette on the wall, making a perfect target for archers hidden outside. Seconds later, the lord was pierced with an arrow and fell to the ground. According to local legend, the blood of Sir Humphrey left an indelible stain on the stone floors, forever marking the site of the tragedy. 

Bannachra Castle geograph org uk George Rankin Bannachra Castle by George Rankin

The castle was abandoned soon after, and nature has slowly laid claim to its grounds. Today, only the remains of a rectangular building can be seen, made of 2 storeys and an attic in the roof. The east gable, part of the west, and north and south walls are overgrown with foliage, and the south-east corner that is thought to have contained both the entrance and a winding staircase has completely deteriorated. Archaeological investigations suggest that the building once also contained a vaulted basement, typical of grand Scottish castles of the time, once again indicating Clan Colquhoun’s power and wealth. 

Excitingly, Bannachra is set to gain a new lease of life! Dr Liz Barrett and Rob Lenihan have purchased the estate, putting in place a 5 year plan to make it bio-diverse, sustainable, and with net-zero emissions. They also plan to make the castle into a valuable resource for future educational, cultural, and clan use. On guidance from Historic Environment Scotland, they have decided to stabilise the ruin and restore some of the stonework, before building a separate new structure inside the walls, which will be used for heritage-based events. 

Be sure to follow the Clan Colquhoun International Society for further updates on this exciting project!

We hope you have enjoyed exploring a few of Clan Colquhoun’s greatest strongholds with us, and feel a bit closer to this mighty family! 

 

For more information about the clan, head over to our Clan Colquhoun page, and keep an eye out for plenty more Colquhoun content to come this month!

Image Sources:

Dunglass Castle and the Henry Bell Monument, taken Sunday, 20 June, 2010 © Lairich Rig (cc-by-sa/2.0) 

Dunglass Castle in West Dunbartonshire Drawn by F.A. Pernot and printed by A. Dewasme - http://www.ancestryimages.com/proddetail.php?prod=e9755&cat=43, Public Domain

Rossdhu House, taken Friday, 4 May, 2007 © George Rankin (cc-by-sa/2.0) 

Bannachra Castle By George Rankin, CC BY-SA 2.0