An Grianán Theatre is the largest theatre in County Donegal. Located in Letterkenny's Port Road district, its current Director is Patricia McBride. The theatre was named after Grianán of Aileach (‘Stony House of the Sun’), a prehistoric ring fort located in Burt believed to date back to 1700 BCE. With a seating capacity of 383, the theatre provides a range of programming including drama, comedy, music, pantomime, and family shows as well as workshops and classes.
It is used annually as a festival venue, including for the Earagail Arts Festival, and has twice hosted Fleadh Cheoil na hÉireann. It is a main partner of the Earagail Arts Festival, which takes place each year in July, the Irish Aerial Dance Fest which takes place each June and the Letterkenny Trad Week which takes places each January.