You make the area around a campsite appear to be a thicket of untouched and forbidding foliage, or some other unwelcoming feature matching the surrounding terrain. Creatures outside the area cannot sense any activity going on inside the area—they cannot smell campfires or cooking food, they cannot hear conversation, loud noises, or spells being cast, and they cannot even feel heat or a rush of wind coming from the area. Those inside the area can see out normally. Once a creature steps into the area of the spell, it can see everything in and around the area normally.