In the Aran Valley there is a group of Romanesque churches built between the 11th and 13th centuries characterised by their large deformations, in some cases exceeding 7% of their original condition. The research shows the results of the geometric study carried out with a Terrestrial Laser Scanner (TLS), revealing geometric differences with regard to the traditional definition of barrel vault. The deformations of the initially anti-funicular vaults are sometimes transformed into convex funicular shapes, where the final spatial volume is smaller than the initial one, despite the fact that the linear length of the curve and surface of the vault is greater than that of their original condition.