The Roman amphitheatre is a must – still used to this day for concerts etc. After that head to the Place de la Maison Carrée where there is a perfectly preserved 1st century BC Roman Temple opposite a Norman Foster creation, the Carre d’Art, a contemporary art museum. Nîmes is not always the most alluring city but these are real gems.
It is worth getting the audio tour at the amphitheatre and worth buying multi-site tickets (rather than buying a separate ticket at each site).
30 minutes by car.