The Highlands is a fertile mountainous region known for the city of Overlook where people suffer from the Skull Shivers and its Stalker inhabitants. All around the area, you'll be able to find different Hyperion installations, some large and some small.
There will be a few missions that you'll get from the bounty board in Overlook. Some of them will be minor missions like "Arms Dealer" and "Hyperion Contract #837" but there is at least one mission chain in "The Overlooked".