In 2006, The St John’s Co-Cathedral Foundation embarked on the restoration of the Main Nave. The cleaning and restoration works were carried out in order to retain the original coherence and beauty of the decoration of the Co-Cathedral. St John’s Co-Cathedral has a barrel-vaulted nave buttressed with arches leading to side chapels. Each side chapel belongs to a specific langue of the Order, each responsible for the decoration of its own chapel. The walls were lavishly carved out of limestone to form relief carvings, gilded to create an aura of dazzling brilliance.