Abstract: A flexible barrier is provided for arresting falling rocks comprising posts and a rock collecting and arresting net. Each post pivots upon a ground-anchored base plate and is stayed by windbracing cables secured to the top of the post. Two of the cables extend in an upstream direction from the post and one cable extends in a downstream direction from the post. The net is placed on and secured to a series of spaced, longitudinal, horizontal ropes which are supported by the upstream windbracing cables. The horizontal ropes are connected to the cables in a manner which permits the ropes to slide freely, with the ends of the ropes being secured to ground anchoring means beyond the ends of the barrier.