Quadrant I13, connects Martha's Bay to the Ukuku Prairie via cave.
Quadrant I14, there is pretty much nothing here.
Quadrant I15, has a phone booth so you can talk to a lonely old man.
Quadrant J15, another set of mysterious stairs, who puts them way out here, and why?
This quadrant leads to both the mysterious stairs seen above, and to an owl statue. You can ignore the white parts in the bridge texture there as they are transparent when viewed in game:
