CONTAINS SPOILERS

There is a Cocoon in South Aelio called Runway tucked away in a secret location at the foot of Mt. Magnus. To reach it, first make your way to the Balflow Falls Ryuker Device in South Aelio. At the bottom of the cliff there is a waterfall (view images) you can walk into. Keep left as you walk through the cave system. Eventually you'll reach the Cocoon situated in the middle of an open area.