Your first stop is Gulgan Gulch, so follow the map there.

Chests (3):

• Mage Robe
• Ice Staff
• Fire Staff

Inside after the set of stairs, talk to the middle man to activate a scene. Then, collect all chests following a hidden passageway.

Chests (9):

• Echo Herbs (x3)
• Spark Dagger
• Bomb Fragment
• Sonic Knuckles
• Flame Mail
• Salamand Sword
• Zeus's Wrath

Now get out of Gulgan Gulch, follow the map to Tower of Owen.

To proceed to the next you have to cast Toad spell on all your party members at (1). After you appeared on the next floor, cast the Toad spell to reverse the effect.