One of my favorite “secret” spots in Rome – right in the congested center – is Francesco
Borromini’s Sant’Ivo alla Sapienza, which he designed in the
1640s. Hidden away at the end of a long courtyard (designed by Giacomo della
Porta), it is a unique little gem of curves and unusual geometry, topped by a
corkscrew bell tower. 
The interior of little church is equally charming. The vault of the cupola supporting the bell tower is a kaleidoscopic froth of pleats and bulges and light and shadow.
Borromini’s style of Roman Baroque architecture could be
said to reflect his tortured soul. His work was pure genius, but too
unconventional to have long-lasting impact on later architects. He was a
melancholy man with a quick temper which limited his career, and he died
by his own hand in 1667.
I’m amused by the reproachful
statement of the Neoclassic art historian Francesco Milizia (in his 1781 Memorie degli architetti antichi e moderni)
who criticized Borromini thusly: “Questo
artista non poteva soffrire il retto” (“This artist could not stand
straight lines”). Like that was a bad
thing!
