Worm fence
A fence, zigzag in plan, made of rails resting across one another at an angle according to the Random House Dictionary.
This style of fencing is also known as Snake Fence, ZigZag Fence and Battlefield Fence - the latter term due to its presence on many Civil War battlefields. Worm Fence has been used in America since the 1600's. Easy to build, split wood rails are stacked on each other to create the fence. The ends of the rails alternate, creating the openings. For stability of the stacked rails, each section of fence is angled slightly from the previous one, giving the appearance of a worm or snake.
No Post Holes, Rocky Terrain bonus
No vertical posts are required to build the fence. This both eliminates the need to dig post holes and makes the fence easy to install - a particular advantage in rocky terrain. Sometimes a pair of crossed posts would be used at the junction point of each section. This would allow the fence to be closer to a straight line.
Rustic
With a plentiful supply of wood and ease of construction, it is easy to understand why worm fence was the most common type of fence used in America by the late 1800's. It is gaining popularity today for use as a rustic fence that will add to the appearance of a piece of property.