From Bulbapedia, the community-driven Pokémon encyclopedia.
Fortune Island (Japanese: たこうじま Fortune Island) is the sixth island in the Sevii Islands archipelago. It is south of Chrono Island and east of Quest Island.
The island has a small town, Six Island, where many say that the view of the stars is amazing, away from the bright city lights of more populated regions such as Kanto.
East of the island's port is the Water Path, a small arc of land next to the seaside. On the north side, a cottage sits. Inside, there is a woman who desires the "Ultimate Horn". Much like the fisherman at the Lake of Rage in Johto do to Magikarp, she measures the horns of Heracross, which are common in the nearby Pattern Bush.
The westernmost side of the Water Path leads a Trainer through Pattern Bush, where many Bug Pokémon call home. Some believe that there are secrets in the patterns made in the grass. After passing through here, Trainers arrive at the Green Path, a short trail leading to Outcast Island.
Of note in Outcast Island is Altering Cave, a location whose name may possibly be centuries old. As it has had its name since days long past, many do not know the reason why it was named as it was.
If travelers head southbound on Water Path instead of northbound when they exit the town, they will soon arrive at Ruin Valley, home to many ruin-loving Pokémon, such as Natu. At the center of the valley is the Dotted Hole, a mysterious, recently discovered ruin from an ancient time. The discoverers named it such because when they found it, there were six dots on its door. If the player manages to get inside, they will be able to find the Sapphire that Celio needs to complete the Pokémon Net Center's trading capabilities, with the Hoenn and Orre regions.
Locations on Fortune Island