Trastevere is lovely to stroll through. You won't find any major highlights, but mostly cosiness.
If you go for real Italian cosiness, Trastevere is the place to be. It is one of Rome's most popular neighbourhoods. You won't find any big, well-known highlights in this former working-class neighbourhood, but that is precisely what makes Trastevere so much fun. Here, it is mainly the atmospheric streets, small trattorias and cosy squares that attract tourists and locals alike. A must-see is Santa Maria in Trastevere, a church with elements of antiquity, medieval, Renaissance and Baroque. Take a stroll up Janiculum Hill, which towers over the rest of the neighbourhood and from where you have great views.