The Chiesa del Gesù — also called Casa Professa, from the Jesuit residence next to it — is the most lavish Baroque church in Sicily, with walls completely covered in polychrome marble inlay (cinque mischio) and frescoes by Filippo Randazzo and Pietro Novelli. It was completed in 1636 after almost a century of construction.
The marble decoration is more ornate even than Santa Caterina; the bench seats, columns, statuary niches, and chapel walls all inlaid in red, green, yellow, and black against white. The architectural restraint of the Gesù in Rome — also Jesuit — has nothing to do with the case here. Free entry; a few coins for the audio guide.