Arles is a more lively town than the similar Orange. Extremely touristy too, especially the area around the amphitheater. This Roman building occupies a central space in town worthy of a cathedral. It's still in use as a bull ring. The nearby Roman theatre holds not much more than remains.
Closeby (and signposted) lies the most important romanesque monument of Arles: the Church of St. Trophime. Its exterior decoration is excellent. Inside mainly the huge tapestries draw the attention. Somehow I missed the entrance to the cloisters, which are said to be rich in carvings too.
Finally, I walked south to the cemetery of Les Alyscamps. I had my backpack with me (including electronics such as a laptop and Kindle) as a was on my way to the airport in Marseille. I was a bit worried roaming around a desolate necropolis with all my valuables, but Les Alyscamps proved to be almost as touristy as the rest of Arles. It's a nice place for a stroll though, and peek into the old church that now is the domain of numerous pigeons.