Thicket

Any tribute who wanders too far into this dense clump of trees will find themselves having difficulty navigating anywhere. The slender, close-together trees grab at hair and clothing and backpacks and whatever else sticks out, making running impossible for anyone not interested in putting their eye out on a protruding branch. It seems unlikely that anything would be able to track you by sight between the close trees, though the snapping twigs will make it very easy to be heard.