The Kirna, known locally as Kirna House (previously also as Grangehill), is a Category A listed villa in Walkerburn, Peeblesshire, Scotland. It is one of three villas in Walkerburn designed by Frederick Thomas Pilkington between 1866 and 1869 for the Ballantyne family. It is listed as a fine example of a Pilkington mansion retaining original external features, a fine interior, and for its importance as a Ballantyne property.

The Ballantyne family played a leading role in Scotland's textile industry for nearly two hundred years. The Ballantynes were substantially responsible for founding the village of Walkerburn after Henry Ballantyne first bought land at that location to build a tweed mill in 1846. Architect F T Pilkington was commissioned by the Ballantynes to design and build the new village with houses for the mill workers, and villas for the mill owners and their families.

The Kirna's proximity to a number of ancient man-made structures, including some dating back to pre-historic times, suggests that this general location along the Tweed valley has been of strategic importance to settlers throughout history.

The Kirna was built between 1866 and 1867 by George Wilkie (1821-1892) of Hayfield Villa, Peebles for George Ballantyne (1836-1924), third son of Henry Ballantyne (1802-1865). It was designed by British architect Frederick Thomas Pilkington. It retains all of its original 1867 Scots Baronial and Venetian Romanesque design features including an idiosyncratic tower in Ruskinian Gothic style. The heavy oak main staircase features distinctive turned and carved balusters identical to those found in F T Pilkington's own house, Egremont, 38 Dick Place, Edinburgh, and grotesque finials holding shields sporting the initials of George Ballantyne (1836-1924) and his wife Marion ("Minnie") White Aitken (1841-1914). The hallway features a large glass cupola and an artist's studio is housed in the turret room. The dining room ceiling incorporates the initials of Colin Ballantyne (1879-1942) and his wife Isabella Milne Welsh (1881-1969), respectively.

Of special architectural note is the main entrance and heavily decorated (sculpted) elevation featuring a central flight of ashlar steps leading to a polygonal, arcaded loggia entrance area which is supported by two rope-moulded arches. Immediately above the entrance is the first floor with prominent chequered detail between the band courses, and a repeat of the rope moulding around the windows. The second floor features a turret with two finialled dormers. The Kirna shares many of these design elements with another F T Pilkington building originally known as Craigend Park in Edinburgh, designed and built for William Christie between 1867 and 1869, a "Glover and Breeches Maker" (tailor) at 16 George Street who is believed to have sourced much of his material from the Ballantyne mills.

Designs of The Kirna were exhibited at the Royal Scottish Academy in 1867. The subsequent review in The Builder noted that "Pilkington is never commonplace, though frequently wild and eccentric". The Kirna was praised as "a pleasing example of the modern style Gothic as applied to domestic purposes: abundance of light is given, and variety is secured without violent contrast".

Drawings of alterations dated 1903 by James Jerdan (architect at 12 Castle Street, Edinburgh), indicate the addition of a coal chute and "heating chamber" area located beside the main building. The 1903 alterations included the addition of a 'boudoir' (now game room) to the west gable, and a bedroom on the first floor.

The boundary wall and a glass house still survive. The entrance gates were likely removed during the war in 1941 when the government passed an order compulsorily requisitioning all post-1850 iron gates and railings for the war effort.