View of the unique nave vault of Tournus Abbey, 11th century. The tall nave is filled with light, thanks in large part to its rather ingenious system of vaulting. In a design that seems to have been invented in Tournus, the nave has a succession of transverse barrel vaults. This transfers the weight of the vault to the pillars, allowing for large windows in the clerestory. This design did not catch on: it was only implemented in one other church (Mont-Saint-Vincent, not far away).