Filippo Brunelleschi's dome for the Florence Cathedral (Santa Maria del Fiore), completed in 1436, is an engineering marvel that bridged the Gothic and Renaissance eras. Its octagonal double-shell design and innovative herringbone brickwork achieved an unprecedented span without traditional timber centering.

Michelangelo's Laurentian Library staircase in Florence (begun 1524) exemplifies Mannerist tension. Its massive, seemingly fluid stairs spill into a confined vestibule where massive columns are recessed into the walls, supporting nothing—a deliberate overturning of classical structural logic.

Francesco Borromini's San Carlo alle Quattro Fontane in Rome (begun 1638) is a masterpiece of High Baroque complexity. Its undulating, wave-like facade and incredibly complex, oval-based interior plan—topped by an oval dome with intricate honeycomb coffers—perfectly embody the era's dynamic, spatial ingenuity.

An interior space features an incredibly complex, undulating oval plan. The boundaries between architecture, sculpture, and painting seem to disappear as dramatic, concealed light sources illuminate highly emotional, opulent frescoes on the vaulted ceiling.