Galleria Barberini.

Not only is this the palazzo Audrey Hepburn famously ran away from, but also a divine museum containing gorgeous works from early Renaissance to the late C.16th, incl. Raphael, Caravaggio, El Greco et al. Via delle Quattro Fontane, 13 / Barberini / 06 32 810 / closed Mon / beniculturali.it