Trastevere earns its reputation in the evening and loses something to it; do this walk in the morning instead, when the lanes belong to the people who live in them. Under three kilometres of cobbles south of the Viale di Trastevere, the part that still feels like a village folded into the city.
Start in Piazza di San Cosimato, the working square, where a small food market sets up under the plane trees. Drift north through Vicolo del Cinque — ivy, shutters, washing on lines — to Piazza di Santa Maria in Trastevere. Get there early: the gold mosaic facade wants morning light, and the basilica's apse holds the oldest mosaics of their kind in Rome. Sit a while.
Then east along Via della Lungaretta, ducking into side lanes as they tempt you, and south to Santa Cecilia, built over the saint's own house with Roman rooms excavated beneath. End at Piazza Trilussa by the river, facing Ponte Sisto, where the tram back picks up along the Lungotevere a couple of minutes north.