Temple of Mila (Passageway)

Technically not a dungeon, but can be easy to miss.

If you head north from the Control Room in the Temple of Mila, you’ll enter a small area that you can roam around.

At first, the water level will prevent you from going past the Experience-granting spring; you can explore the rest after Celica opens the sluice gates.

On the other side, Nomah will be waiting to be recruited and you can find the Silver Platter for the “The Clumsy Cleric” sub-quest.