This is a must if you plan on seeing a bunch of museums. Each museum costs 4-10 euros, which really adds up. The tourist board where you redeem your voucher is right across the street from the port and easy to find. The pass does not include the main tour bus, however - just a discount.

This is a very good deal, and it gives you a good base on which to plan your days in Marseille. We purchased a two-day pass, which we picked up from the tourist centre and which was validated at that location. The lady at the office failed to tell us that the second day of our pass was a public holiday and we couldn't use the pass because nothing was open: churches, museums, libraries; everything was closed. Had she told us, we could have chosen two other days because we were there for five days.