The visual history of the construction and restoration of the Cathedral from its origins until today is on display here.

Designs and sketches show the interventions of architect Giuseppe Valadier (1762-1839) and Camillo Morigia (1743-1795). These architects worked on the original Renaissance structure (likely created by Francesco di Giorgio Martini (1439-1502) of Siena after the collapse of the dome in 1789, substituting  it with a Neoclassical style.