20 of us are taking a bike/barge trip from Aigues Mortes to Avignon, France. Where should we fly in and out of? Paris, Maseille, or Barcelona, Spain? How do we get to Aigues Mortes from that airport
and then go from Avignon back to the airport. This trip is not until next June but we are trying to get our ducks in a row. We will not have bicycles with us.

Marseille is the closest airport. It may require a train ride plus a bus ride to get to Aigues Mortes.

What is your starting point? If you are in the United States, your best bet would almost certainly to fly to Paris with a connecting flight to Marseille.

To get to Aigues-Mortes, you take a commuter train (TER) from the Marseille airport to Nimes and change there to another local train to Aigues-Mortes. Even though it's only 112km from the Marseille airport, the trains will take about 3 and a half hours.

Considering the size of your group, you might consider chartering a bus from the Marseille airport to Aigues-Mortes.

Avignon back to Marseille by train is ultra easy and fast.

Hopefully you have someone (experienced in such things) coordinating this adventure. Otherwise it could be a problem.

Montpellier airport is a great deal closer to Aigues Mortes than is Marseille and has regular flights from CDG. From Aigues Mortes, MRS is about 125km, but MPL is about 25km. From Avignon, MRS is under 10km closer than is MPL but the easiest airport, albeit the one with the fewest service options, is Nimes (FNI).

Sarastro is correct. I don't know why Montpellier slipped my mind. There is a municipal bus from Montpellier to Aigues-Mortes (line 106) that costs 2 euros.

I had checked the flights of Nimes airport, and it is totally dead with just some Ryanair flights from Blighty.

Wow, no one suggested Barcelona. Thought that would have been to closest and easiest airport.
Starting point for us is Boston.

Pack mosquito repellent, no matter where you end up flying into.

<I> Thought that would have been to closest and easiest airport.</I>

Well it certainly isn't closest, and "easiest" is almost never to arrive in a completely different country from where you plan to spend your time.

<i> Thought that would have been to closest and easiest airport.</i>

Time to look at a map.

Barcelona? Even Nice is only about half as far as Barcelona, and it's a major city.

There are many more flight options to Marseille than Montpellier, that's all, probably, as to why it could be a decent choice. Both better than Barcelona.

GOing to MOntpellier, you have 2 choices -- Air France or KLM (transferring at Paris or KLM). And at Paris, I think Hop, the cheap AF subsidiary is best out of Orly but flights from the US go into CDG. So AF flights from CDG to Montpellier are limited, but there are some.

Going to Marseille, you have several more options, such as tranferring in London, or even Munich on LUfthansa or Lisbon. So I'd just compare schedules and prices.

From Avignon, there's excellent TGV rail service to Paris if anyone in your group wants to spend time in Paris after your bike/barge trip. Or, many flights Marseilles to Paris.

Meant to add I would do the train hands down if finishing in Avignon and going on to Paris.