 This 70 m-high cupola with a small lantern atop, is carried by four finely sculpted arcs in rose and white marble.There are six organs, four of which are located in the transept, constituting a rather uncommon ensemble.There were built by Joaquim Peres Fontanes and António Xavier Machado Cerveira between 1792 and 1807 (when the French troops occupied Mafra).