Interior view

Bernini erected his three churches over the most familiar centralized plans, the Greek cross, the circle, and the oval. The earliest of them, the parish church at Castel Gandolfo is a simple Greek cross, reminiscent of such perfect Renaissance churches as Giuliano da Sangallo's Santa Maria delle Carceri at Prato. The ratios are of utmost simplicity, the depth of the arms of the cross, for instance, being half their width. But compared with Renaissance churches the height has been considerably increased and the dome has been given absolute predominance.

The spirit of austerity prevails in the interior up to the sharply chiseled ring above the arches. But in the zone of the vaulting Bernini abandoned his self-imposed moderation. The Berninesque type of dome with ribs and coffers all'antica, applied here, was followed on countless occasions after 1660 by architects in Italy as well as the rest of Europe.

The photo shows the view into the dome.