Gondowan Cave

Gondowan Cave is a minor dungeon-style location that serves as the road through which the party in Golden Sun can return to Angara from Gondowan and back, following the episode on the Tolbi-bound Ship. Its entrance and exit points are below the Karagol Sea west of Tolbi and above it south of Kalay, and can be cleared and made open as a "path" as soon as you first reach Tolbi because it only requires the Lift and Move Psynergies. If you're completing side-quests such as the one at Lunpa Fortress, it is very important to use this cave to return to Angara.

After the Colosso Finals at Tolbi, the warriors that were unable to gain admittance in time as competitors, Sean and Ouranos, attempt to find a way back onto the mainland continent of Angara because the ferry service through the Karagol Sea is put on hold and the portion of Silk Road just above Kalay Docks is blocked off by a landslide. They investigate Gondowan Cave and understand it connects to Angara, but do not have the physical strength to lift the boulders themselves, so they return to Tolbi to stay at its Inn for the time being. Should Isaac and his companions decide to return to Angara, the Lift Psynergy they possess allows them to bypass the obstacles that block normal humans and make it through Gondowan Cave easily.

Walkthrough
Upon entering the cave location just below the southeast corner of the Karagol Sea, you are presented with a fork going left or right. When you're done with this area, the way right becomes open as the "shortcut path" between one exit and the other, but until then go left. Cast Lift on the brown boulder blocking your way, and continue along a linear path until you get to a watery room. The top end of this room has a chest containing an Apple, while on an island in the water that can be easily hopped to is a chest containing a Lucky Medal.

Exit out of the room's southeast doorway, and you will be led to where a thick, short pillar of earth blocks your way. Use your Move Psynergy and move it left; where it falls makes it a critical component of the shortcut path. Now go right and move the tall earth pillar two spaces right so that it falls into the watery gap. Already, the area is complete and now you can use the shortcut path of the dungeon to switch between continents for the rest of the game.

Collectibles
Apple: On the lower half of a room, with a chest containing an Apple on the upper half of it. Lucky Medal: On the upper half of a room, with a chest containing a Lucky Medal on the lower half of it.