From Bulbapedia, the community-driven Pokémon encyclopedia.
Quest Island (Japanese: もとめじま Quest Island) is the seventh island in the Sevii Islands archipelago. It is south of Floe Island and west of Fortune Island.
Quest Island, like the other Sevii Islands, has a town on it, named Seven Island; however, also like the other islands, this town is small compared to the island's explorable area.
Quest Island does not have as many inhabitants as the other Sevii Islands. It has been left virtually untouched in its natural state and is difficult to hike across.
In the port town, an old lady runs a wireless battle house for battles when special data is transmitted through Mystery Gift. The old lady is eager to watch battles in order to reminisce about her past, much like the old man in Mossdeep City in Hoenn.
North of the port is Trainer Tower. The sign outside of it proclaims "Rise to the Challenge, Trainers!" Trainers from all over come to battle others in the eight floors of the tower as fast as they can. It is unlike normal Battle Towers as items may be used during battle and players may run down the stairs to the first-floor Pokémon Center to heal their Pokémon. A man awaits at the top of the tower to give a prize which differs depending on the battle mode chosen.
South of the port is a Move Tutor who will teach Swords Dance. Further to the south, over a bridge is the entrance to Sevault Canyon. In the canyon is a small cave called the Tanoby Key. Solving the puzzle inside will unlock the secret in the Tanoby Ruins.
South of the canyon is a small house in which a man and his Chansey will heal Pokémon by making them do a dance.
At the southern end of Quest Island are the Tanoby Ruins, a series of seven small islands containing strange chambers. The chambers are home to the peculiar Pokémon Unown, which will awaken if the Tanoby Key is unlocked.
Locations on Quest Island