Once you've gotten a taste of Caravaggio, a late Renaissance master whose work is featured at the Galleria Borghese, you can't leave Rome without seeing what many say is his most powerful work. You'll have to go to church to do it.

The Calling of Saint Matthew hangs in the Contarelli Chapel of the San Luigi dei Francesi church, a reminder that 400-year-old art was provocatively modern when it was first conceived. Two other Caravaggio works — St. Matthew and the Angel and the Martyrdom of St. Matthew — which round out the triptych, are also on permanent display here. Seeing such a renowned work in a church you might otherwise have easily overlooked is proof that Rome really is a living museum.

Like other basilicas, entry is free (come in the morning, since the church closes at lunchtime); you'll have to drop a few coins to light up the paintings in the darkened interior and see how Caravaggio infused his own light into the baroque melodrama.

• 1. San Luigi dei Francesi
  5 Via Santa Giovanna d'Arco, Rome, Italy 00186; 39-06-688-271 41.89960712.474918