Monkey Bars. The monkey bars, also known as the jungle gym or climbing frame, is a piece of playground equipment made of many pieces of thin material, such as metal pipe or, in more current playgrounds, rope, on which children can climb, hang, or sit. The monkey bar designation was for the resemblance that playing children had to the rambunctious, climbing play of monkeys, though the term nowadays often refers specifically to a single row of overhead bars designed to be swung across.