So yea ive found this out the other day and pretty much got it all down. to find this location, when you start off on the free explore, just go left and keep going through all teh tunnels and such and youll eventually make it to Skywatch. enjoy the grind my friends.
I use here too, it's literally one of the best places since they also sometimes appear between the cliff and the helicopter and if you can trick that ?? Lvl knight to fall off you can get the chest in there too