I believe many players are not sure about this yet, so today I will let the editor of Sourcecode.com tell you where the Emmett Mountains in Rock Kingdom are. I hope it will be helpful to you!
Little Locke can choose two ways. Click on the Royal Academy or the Lablan Ore Mouth to directly reach Emmett Ridge.
Emmet Ridge is the only place you must pass to complete the Emmet Ridge Straw Hat and Infernal Affairs missions. You can directly reach the astrological platform in the scene.
For the straw hat task, you only need to wait for the scarecrow to think of the straw hat before you can get the straw hat and complete the task.
If you want to return to the Royal Academy, you only need to click the Emmett Ridge icon in the upper right corner of the screen to exit.