Castle Palamecia

Seventeen chests across 8 floors, all permanently missable. You'll also acquire the Airship for the first time, giving you free access to the entire world map. This dungeon is the toughest yet; by now you should have plenty of gil, so stock up on Hi-Potions, Ethers, Phoenix Downs, and Cottages before heading in.

Acquiring Cid's Airship

Visit the town of Fynn again and return to Paul's house in the bottom-left corner. Before speaking with Paul, you'll find Cid in the bedroom. Talk to him and he'll lend you his Airship.

Speak to Paul and he'll mention that you can only get into Castle Palamecia via air. Exit Fynn and take your boat to Poft, where you'll find the Airship waiting for you.

You're now free to roam the entire world; the Airship can land on any flat terrain. Fly southeast toward the Coliseum and you'll spot the castle nearby.

Land and interact with the castle to be dropped onto the top floor (the dungeon works downward, then back up).

Castle Palamecia

7F. Walk straight up from the entrance and through the door, then step on the trap floor between the two columns to drop down to 1F.

1F-2F. From the warp point, go south and grab Chest 1 (Diamond Cuirass) on the right. Back up, then right to the corridor's end. Down, first left, up the stairs, and Chest 2 (Hourglass) is at the end. Return down the stairs, continue right and south to the bottom-right corner, then all the way left for Chest 3 (Garlic). Backtrack and take the first left going north to reach 2F.

2F. At the split, go right then south. Chest 4 (Ether) is straight down; Chest 5 (Buckler) is directly north of it. Turn left and circle the floor until you reach the stairs to 3F.

3F. Up until you hit a wall. Left path leads to Chest 6 (Thunder Spear) with a monster inside. Back to the split, take the right path and continue up the stairs to 4F.

4F. Up, left, then first path down for Chest 7 (Saint's Spirit). North from there and left to the dead end for Chest 8 (Sleepgrass). Return and take the first path up, then left through the winding corridor to a door. Inside are Chests 9, 10, and 11 (Mage's Staff, Healing Staff, Wizard's Staff). Exit and continue up and right to the stairs to 5F.

5F-6F-7F. Left and up the stairs. Down the path until a small side corridor branches off; Chest 12 (Sun Blade) is there with monsters guarding it. Continue on and you'll reach stairs in the top-right corner leading to 7F. A room on your left holds Chests 13, 14, and 15 (three Elixirs). Backtrack to 6F, then to 5F.

5F-6F-7F. This time take the south path and circle around to find stairs to the next floor. On 6F, continue until you find the next staircase to 7F, then walk straight through to reach the final floor (8F).

8F. Continue until you see the red carpet. Skip it for now and go all the way left to the end of the hallway, then north. Chests 16 (Hellfire) and 17 (Wind Flute) are here. Return to the carpet and approach Leon in the throne room.

Leon has declared himself the new Emperor, but the original returns from Hell before anyone can react. He announces his intention to rule both the living world and the underworld; the Wyvern rescues your party and flies you to safety. The castle crumbles behind you, and in its place rises Castle Pandaemonium.