You have to take a boat ride out to the Chateau d'If, where the Count of Monte Cristo was imprisoned (fictionally, obviously).
Marseille is my favourite city in the whole world and what I like best is just walking along the Corniche. It is not far from you, a walkway and a road by the sea that provides lovely views of the deep blue sea, with the Chateau d'If to the south, and les Calanques to the east.
Other things:
Vieux Port (old harbour): watching fishermen selling their stock by auction is a must. Arriving to Marseille in the Vieux-Port on a summer evening is something you will never forget... You can watch this show by going to Frioul islands or Chateau d'If and going back late in the afternoon. there is also a nice view on the harbor from the Palais du Pharo (Pharo Palace). The famous Canebière avenue goes straight down the harbour.
Notre Dame de la Garde: the big church which overlooks the city. Old fishermen used to have their boats blessed in this church. You can still see many boat models hanging around in the church. From there it is one of the nicest view of the city.
Cours Julien and la plaine: a hangout area with bookstores, cafés, fountains, and a playground for the small ones (metro stop Cours Julien/Notre Dame du Mont). It is THE trendy area of Marseille.
Place Castellane: a roundabout with a grand fountain/column/sculpture in the center, with excellent cinemas and cafés surrounding.
Boulevard Longchamp and Palais Longchamp (Longchamp castle and avenue). From the Réformé church (up the Canebière) you can follow the Boulevard Longchamp where you can see nice example of old upper-class buildings to arrive to Palais Longchamp. The palais is worth visiting though it won't take you long.
Parc Borély (Borely park). A large and great park, 300 meters from the sea. After a siesta in the park go have a drink at Escale Borely to see the sunset.
Le Panier. Panier means basket in French, but in Marseille it is the name of the oldest area of the town. In the middle of this area there is the Vielle Charité, a wonderful old monument, now hosting museums and exhibitions.
Unité d'Habitation: designed by Le Corbusier. The building is called "la maison du fada" (the house of the foolish) by indigenous people. The building contains a shopping street, a church, a children's school and housings. You can get to the roof and enjoy the breathtaking view of Marseille between hills and sea.
Noailles: The area around the Noailles sub-way station is one of the city’s most interesting. Arabic and Indo-Chinese shops, could be part of a bazzaar in Algeria.
Advice: The church of Notre-Dame de la Garde, perched up on a hill, is interesting to visit; you will see many ship ex-votoes (offerings placed by sailors) on the walls. The view from the plaza over the coast is magnificent. The old port is interesting to walk through, and there is a good shopping street nearby. There are a number of good museums if those interest you and the lovely Parc Borély.
Gardens around the Musee des Beaux Arts a few years ago. Very beautiful and lovely atmosphere - full of families enjoying a Sunday afternoon out. Gorgeous gardens and fountains and a beautiful building. It's about (I think) half an hour's walk from the port.
It only takes 30 min max to go to the frioul, there are boats every 15 or 30 min approx departing from the vieux port. They will stop at the other island (chateau d'if) first, drop some passenger and carry on the the Frioul. The island is quite small and there is a little train that will take you to the last beach,on the island then you can walk to the highest point. You can spend as little or as long at the frioul, it is really up to what you want to do: sit on the beach and relax or have a quick look around and return to marseille.
My advice for a better day would be:
- Drive to the parc Longchamp, have a quick stop right in front of the parc at the entrance and look at the "palace", there is not anything else to see really.
- Go to the parc du pharo (2 minutes drive from the vieux port, 15 min from Longchamp), there you will have some wonderful views of the vieux port, the town...there is also Napoleon palace there (much nicer than the Longchamp). Nightmare to park though, try the small streets close to the parc.
- Off to the Frioul, but I would advice you to stop at the island of Chateau d'If too as you can visit the prison (the legend of Montecristo), and then go to the Frioul.
- Back to Marseille, you have to go to the Prado and have a drink or ice cream and then a little walk on the beachfront. To get to the Prado, drive on the corniche JF Kennedy, beautiful views and all the way on the coast line. It will take you approx 20 min from the vieux port but it is a really nice drive.