This is an intriguing take on a wilderness adventure, based around some hills known for the number and variety of trolls living there. Based on large hex-gridded maps, the GM's notes consist primarily of information about the occupants of each hex... but it is far, far more than a random wander around hitting whatever you find!
For a start, there's a whole lot more than trolls in them thar hills. There are ruins to explore, people to talk to and plenty more things to do, find, hunt, fight or marvel at. The whole gives the clear impression that it's a living community that will carry on whether or not any player-characters ever go there, bringing an excellent air of reality to this area within your game world.
There are rumours too, and wandering monsters, and tribes of humanoids wandering around. There are whole adventures to be had, and other things that the characters might want to follow up... even space for you to drop in other material, home-brew or published, that seems appropriate.
If you find it difficult to persuade your players that they want to go troll-hunting, why not send them on an errand that requires them to cross the Troll Hills to get there? Depending on the route they choose, run the appropriate encounters and make the journey as much an adventure as whatever they are going to do when they arrive where they are going.
Anyone fancy a spot of hill-walking?
[5 of 5 Stars!]