Enemy list
Chest list
Hidden items
Sail out from Nepto Temple on the Enterprise. You already picked up Killer Fish (#031), Hermit (#032), and Sea Elemental (#033) in Castle Sasune's lake, but the open sea has them too if you missed any. Hermit is the rarest; keep fighting until it appears. Two new entries swim these waters:
Kill Tangies first in every encounter because their Glare inflicts Sleep on your whole party.
Living Woods
After farming both sea entries, sail west and walk into the forest with the circle in it. This is the Living Woods. Talk to the fairies if you want, but there's nothing to pick up. The map shows "0/1 Item" for this location; that item is story-related and comes later. Head back to the ship, sail north, and dock on the northwest shore.
Four new bestiary entries roam the overworld here:
Farm all four, then head west toward the mountain range. Walk between the peaks and take the path south into a cave.
Gulgan Gulch
Gulgan Gulch is a quick stop for the Toad spell and 3 chests. Head downstairs in the room with the crystal orbs and speak with the Gulgan on the second floor; he'll hand you Toad (Hidden Item 19/61), which you need to enter the Tower of Owen. Before leaving, walk south through the hidden passage to grab Fire Rod (69/367), Ice Rod (70/367), and Mage Robe (71/367). Equip the rods on your mages for elemental physical attacks.
To the Tower
Exit Gulgan Gulch and take a left at the fork. Walk into the forest to register the Chocobo Woods location, then head east on land past your boat until you reach the Tower of Owen at the tip of the peninsula.
Tower of Owen
The tower is 10 floors with 9 chests and 6 new bestiary entries:
Petit Mage casts Blizzara and hits harder than any regular enemy so far. Aughisky's physical attack is even worse. Fury only spawns on the waterlogged entrance floor while you're in Toad form and is fairly rare, so grind there until one shows up before climbing.
Learn the Toad spell from Gulgan Gulch and cast it on your entire party. Walk to the center of the room and interact with the dead end while in Toad form to pass through to 1F. Cast Toad again to return everyone to human form.
1F-2F. Follow the path up to 2F and grab Maiden's Kiss (72/367) in the bottom right corner.
3F-4F. Head up to 4F and grab Tyrfing (73/367) in the bottom right. It's a straight upgrade (no curse, unlike the Tyrfing in other FF games).
5F-6F. Interact with the middle gear to open the path below. Loop around, grab Maiden's Kiss (74/367), and head back up to 6F which is empty.
7F-8F. Pick up Echo Herbs (75/367) and Bomb Fragment (76/367) on 7F, then grab Echo Herbs (77/367) from the top right corner of 8F.
9F-10F. Three chests on 9F: Salamand Sword (78/367), Flame Mail (79/367), and Zeus's Wrath (80/367). The Salamand Sword deals fire damage; the Flame Mail resists it. Save the mail for the Salamander boss fight later and head upstairs to 10F.
How to Beat Medusa
Desch sacrifices himself after the fight to stabilize the Tower and stop the Floating Continent from collapsing. He teleports you outside, the whirlpool to the east vanishes, and the outer seas open up. Save and sail south toward the Dwarven Hollows.