It is a pair of perfectly specular sculpted marble lions, probably conceived to be installed in a structure that was not built and reused in the facades of the twin cathedrals. They are, in fact, perfectly finished on the front of the body, while on the rear only on one side, as if the other were to be hidden. A drawing by Opicino de Canistris, dating from around 1330, depicts them one in the left buttress of the facade of Santo Stefano the summer cathedral and the other in a similar position on the front of Santa Maria del Popolo, the winter cathedral. The latter (inv. B 75) probably arrived in the Museum as early as the late nineteenth century, on the occasion of the demolition of the medieval structures, functional to the erection of the facade of the new Cathedral. The first (inv. B 535), on the other hand, is documented in the same position as the fourteenth-century drawing still in some photographs of 1893 and was then transferred to the base of the Civic Tower, which suddenly collapsed on March 17, 1989. Recovered from the rubble, it was transferred to Museum. Thanks to the nineteenth-century investigations, the drawing and the description by Opicino de Canistris who gives an important testimony of the decoration of the cathedral facade in 1330, on it it is possible to identify the location of two lions, a recurring element in the Romanesque churches of Pavia.