So, no Battle Frontier or something similar you can see on the map?
There is a VERY big cloud on the south western corner. Way bigger than in SM.
SM map: https://bulba-uploads-production.s3...ch_file_file_name/10/normal_Alola_artwork.png
USUM map: http://www.gameinformer.com/cfs-fil...okemon-ultrasunultramoon/usummap_5F00_610.jpg
The cloud would big enough to hide a small island. But of course... it hasn't to mean anything.