A mansion and estate which extends to 1700 ha (4200 acres) in the Scottish Borders, Glen House lies on the Quair Water 2½ miles (4 km) southwest of Traquair. The house was built in the Scottish Baronial style by David Bryce (1803-86) for the industrialist Sir Charles Tennant (1823 - 1906), who had purchased the estate in 1852 and soon after demolished the existing house. The Glen features a corner tower which rises to five storeys, with corbelled-out square turrets, steeply-pitched roofs, dormer windows, crowstepped gables and pepperpot turrets. Robert Lorimer (1864 - 1929) repaired and remodelled the house after a fire in 1905. Now A-listed, this grand mansion has played host to a number of notables over the years, including HRH Princess Margaret, Prime Ministers William Gladstone and Herbert Asquith, author Oscar Wilde and fashion designer Katherine Hamnett. Asquith married Tennant's daughter Margot in 1894.
The house is situated within an 18th century designed landscape which extends up into heather moorland on all sides.
Both house and estate remain in the Tennant family.
