Golden Sun: The Lost Age/Apojii Islands

There is a ton of weeds for you to Cyclone here - a patch just below the weird blue rock at the centre of the area hides a Herb, whereas there's a Mint up for grabs in a patch of weeds to the bottom right. In the area to the right, there's a Bramble Seed underneath the weeds to the far right. You can also stop here for a while to enjoy a scenic view off Gaia Falls, although you can't get the Jupiter Djinni here for a while yet.

Once you've got what you need to (you can use the Inn and Sanctum if you want), go up to the weird blue rock shaped like a water droplet and use Douse on it. There'll be a scene where you see some moai statues on Aqua Rock move - if you went there before you wouldn't have got any further. When you're ready to rock and roll, sail to the beach on the island with the blue rock, and head around to the entrance.