Trastevere is a quarter of narrow medieval lanes across the Tiber from the old centre. You walk here on sampietrini, the small black cobbles that ripple underfoot, past ochre walls furred with ivy and shuttered artisan workshops. The street plan survived where grander Rome was rebuilt, so the lanes still bend and narrow without logic. At its heart the church of Santa Maria in Trastevere claims one of the oldest sites of open Christian worship in the city, its façade lit by gold mosaics.
The name means across the Tiber, and for centuries that river was a social border; the people on the far bank came to think of themselves as the truest Romans of all. The quarter grew up outside the ancient city as a working district of sailors, dockhands and foreign traders, and it kept a character apart: crowded, self-contained, a little rough. Mornings are quiet and domestic, all laundry, espresso and a delivery scooter in a doorway. By evening the same alleys fill with diners and students spilling from trattorias, and the fountain steps in the main square become the neighbourhood's living room.