You watch the vines across the river, but there isn't really much to look at.  The vines are thick and heavy looking, a mass of twisted growth hanging from the limbs and boughs.  They move and shift, some seem to even creak and crack, as the light wind passing down the river blows them about.  Other than that, they seem to be just regular old vines...<br/><br/>(Roll Spot DC 17 to notice what looks like an indistinct humanoid figure amongst the vines)