A Benedictine convent on the south side of the Roman forum, with a 12th-century Romanesque bell tower (one of the oldest in Dalmatia) and a frescoed interior. The church itself is small but striking; the real attraction is the treasury museum behind it, which displays the convent's accumulated centuries of liturgical wealth.
Allow at least an hour for the museum. Photography is not allowed inside. The convent itself is still active and you may hear nuns singing the offices from behind the grille on the chapel.