Chocobo's Hot and Cold
Entering Chocobo Forest (located by the southern beaches of the Mist Continent) will introduce you to Choco. You will learn how to play a game called Chocobo Hot & Cold in which you use Choco to search for treasure in the forest. You will find many items, but the main goal is to find Chocographs. For 60 Gil you can play this game often. I highly reccomend you play the game several times.
After playing the game and getting new abilities you can reach new locations. In Chocobo's Lagoon, the game is half price, half time until you get the Ocean Ability and can go in deeper waters. In Chocobo's Sky Garden you can't dig in the clouds, so try to be quick going from one land piece to the other.