Triumph of Divine Providence (ceiling)

Pietro da Cortona's ceiling is Baroque bombast at its most operatic: a massive illusionistic sky opens above the Grand Salon and figures spill over the painted architecture, refusing to stay inside their frames. The subject is a piece of pure Barberini propaganda — Divine Providence crowning the Barberini bees (the family emblem) with the papal tiara and keys, celebrating Urban VIII's election. Lie on the floor if you can. Cortona invented a whole new grammar for ceiling painting here; it's the direct ancestor of every 18th-century palace ceiling in Europe.