Participants come from Brittany, Ireland, Wales, Scotland, Cornwall, Cumbria, the Isle of Man, Cape Breton Island, Galicia, Asturias, Acadia, and the entire Celtic diaspora.

The main festival sites are located throughout the city, with more formal events taking place at the Palais des Congrès, Grand Théâtre or Église Saint Louis.

The larger events take place at the Parc du Moustoir (the home of Lorient Football Club which can hold up to 10,000 spectators), the Port de Pêche or in grand marquees.

Throughout the festival the "Village Celtique" (fr) or "Marc'had Etrekeltiek" (br) is open in the centre of the city offering food, music and literature, clothing and crafts.

There is also much activity on the festival fringe, with musicians giving free performances in many of the city’s bars and pubs every evening until late.