How do you get 100% map completion in Oerba?
Solution 1:
There are in fact 3 different years accessible for Oerba. The sea isn't accessible in both 200AF and 300AF but is accessible in 400AF where its just sand.
To get to the area by Chocolina, it isn't actually talking about inside the room, but the roof I believe. You can access this area with a Chocobo and you have to jump down from the Main Road. This can be done in any year.