The City of Mithalas
Upon arriving at the empty city of Mithalas, there is a broken tablet of the same name near Naija when you first arrive. Clicking on it will trigger her response to seeing the city before you proceed. The area is devised of two semi-circles conjoined, creatures now taking up residence where the Mithalans once resided. Traveling through here is relatively safe, provided you keep an eye out for spring-loaded eels hiding in ruined homes and the cricket frogs that fire blue projectiles which ricochet off of surfaces.
A good policy going through the city would be to check every single house that you can (they will be marked on your map with a white circle). Some will contain pots that have useful ingredients (The Rainbow Mushroom is a rather amusing addition to your kitchen) while others have healing algae plants, fish to harvest and a save point. In the upper northeast corner of the map, there is a strong current that prevents you from entering this last area (once you obtain the Beast Form, you can go through and acquire The Mithalas Pot) Further on, there will be a Plant Portal that cannot be used yet (you will need the Nature form to access that).
In the lower section of the city, you will come across a kitchen, but more importantly, access to one of Naija's memories (there are three in total, the other two are optional to find). Take the time to craft any three slot items (like Spicy Rolls) while you have the chance because the upcoming fight is arduous.
Once you are done, it's time to head into the Mithalas Chambers located in the far east section on the map. There will be three pots leading into the Chambers, containing various items and residing underneath a sinister message.
Items to Keep in Mind
~ Mithala Doll (Found in one of the houses. Only obtainable once you acquire the Fish Form)
~ Mithalas Pot (Found in the northwest section of the map, obtainable with the Beast Form)
~ Spirit Form (Acquired after fighting three Mithalan Priests (obtainable only after acquiring the Nature Form and Fish Form to access the area beyond the Northeast section (there will be a Plant Portal)