Marseille is considered to be the oldest city in France, created in 600 BC by the ancient Greeks.
Web site of the Marseille tourism office: http://www.marseille-tourisme.com/en/
Web site of the public transportation
Map of public transportation; also map zoomed to the city center
Accommodation
Please consider to book your hotel early enough through the usual reputable resources. An overview may be found at the tourist office website. A general (but not a strong) recommendation: it's handy to choose a hotel to the south of the Vieux Port.
Please note that the conference organisers are not in contact with any external travel agencies. Please exercise caution in case you receive any unsolicited emails offering accommodation bookings.
Options to explore on your own:
Walk/hike in the Calanques
Web site of the Calanques National Park: http://www.calanques-parcnational.fr/en
"The Calanques" are series of mini "fjords" carved in white limestone cliffs on the outskirts of Marseille. It is possible to go there by bus and walk. The easiest access is from the bus stop "Parc National des Calanques" (lines B1 and 24). Other access points are with the bus lines 22, 23, and 19+20. One can also hike from the side of the town of Cassis (reachable by bus 78 or train plus a long walk) where the calanques are narrower and may be more picturesque.
Exploring the city
The tourist office provides an extensive list of places worth seeing in Marseille.
Consider visiting the Notre Dame de la Garde basilica which offers a great view on the city. Palais Longchamp is another suggestion. The old town district of Le Panier is located on the opposite side of the Vieux Port bassin compared to the conference venue. Two other attractions located near the conference venue are the Citadelle of Marseille and (across the water) the Mucem museum with its Fort St Jean.
Furthermore, the Château d'If (yes, that one from The Count of Monte Cristo) is located on an island just outside Marseille and is reachable by a frequent ferry from the Vieux Port.
If you consider swimming in the October sea, the Catalans beach is located nearby the conference venue.