A fine classical mansion and small estate on the west shore of Loch Lomond, Rossdhu lies 2 miles (3 km) south of the village of Luss. Formerly the seat of the Colquhouns of Luss, it is now home of the exclusive Loch Lomond Golf Club, with the 267-ha (660-acre) estate providing country sports and accommodation in lodges and cottages.
Rossdhu House dates from 1772-74 and comprises three floors and an attic, with wings to the north and south of two storeys. A massive pedimented porch supported by paired Tuscan columns provides a grand entrance to the principal (middle) floor. The architect is disputed, but was most likely John Baxter, who had worked with Sir James Clerk of Penicuik (c.1710-82), who is known to have been consulted on the design. Robert Adam (1728-92) may also have been consulted. The grand entrance and the wings were most-likely added in the 1820s.
James Boswell and Samuel Johnson were entertained in his new house by Sir James Colquhoun and his wife in October 1773, staying the night. While the pair found the hospitality generous, Lady Helen found Dr. Johnson boorish and insufferable.
Rossdhu has long formed part of the Luss Estates and was the home of Sir Ivar and Lady Kay Colquhoun until the early 1990s. In need of work, the property was rented to the Loch Lomond Golf Club in 1993. The club was responsible for arresting subsidence, extending the house to the rear and a complete restoration, which involved considerable changes to the interior. The bedroom and basement floors have been substantially altered to meet the needs of the golf club, while the principal rooms are structurally the same. The personal functions of the former family home have been swept away, with the Boxing Room and 'Moor and Loch' Room gone. The Chinese Drawing Room, once decorated with hand-painted silk wall coverings, is now the Library; the former Library now forms a Cocktail Lounge and a Wine Room now forms an entrance to the Dining Room. The house still contains some of the Colquhoun's fine furniture and paintings.
