Bus tours through the Camargue, departing from Avignon with a passenger pick-up in Arles (behind the tourism office, in front of the Atrium hotel, 9:45 AM) are offered by Self-Voyages Provence for about EUR 45. Ask about the optional riverboat trip down the Rhône. Taxis T.R.A.N. can take you round-trip from Nîmes to the Pont du Gard (ask the taxi to wait while you explore for 30 minutes).
Self Voyages Provence (42 bd. Raspail, 84000, Avignon. 04-90-14-70-00. www.self-voyages.fr). Taxis T.R.A.N (04-66-29-40-11).
The tourist offices in Arles, Nîmes, Avignon, Aix-en-Provence, and Marseille all organize a full calendar of walking tours (some in summer only).