Although consecrated in 1538, this Jesuit church is best known for its lavish 18th-century decor, considered the finest example of baroque styling in Sardinia. The spectacle starts outside with the ebullient triple-arched facade and continues through the vast colonnaded atrium into the magnificent octagonal interior. Here six heavily decorated chapels radiate out from the centre, capped by a grand, brightly frescoed dome. Also of note is the sacristy, with its vivid frescoes and intricate inlaid wood.
Before you go inside, take a minute to admire the massive four-columned pulpit in the atrium. This was built and named in honour of the Spanish emperor Carlos V, who is said to have delivered a stirring speech from it before setting off on a fruitless campaign against Arab corsairs in Tunisia.