The austere facade of the 15th-century Eglise Saint-Jean-Baptiste , where the wedding was celebrated , doesn 't prepare you for the characteristic Basque carved oak galleries to separate the various classes of worshippers on three sides of a single nave , with polychrome wooden vaulting and a three-tiered gilded-and-crimson Baroque altar .
The Eglise Saint-Jean-Baptiste , though it looks plain on the outside , is astonishingly ornate on the inside .