Castle Wall

Castle Wall is a logic puzzle created by Palmer Mebane (USA). A rectangular or square grid contains black or bordered cells; some of them contains numbers and arrows. The aim is to draw a single closed non-intersecting loop. Black cells must be outside the loop; white bordered cells must be inside the loop. Numbers and arrows refer to the total length of loop segments in the arrow's direction. (In other words, the number shows how many cell borders in the arrow's direction are crossed by the loop.)

Castle Wall

Cross+A can solve puzzles from 4 x 4 to 30 x 30.