This paper describes some characteristic aspects of wayfinding behavior with regard to an initial instruction to a subject as the environmental information in an irregular street area. 61 subjects involved in this experiment are divided into three groups in terms of the initial instructions. Each group is asked to reach a given destination (D) under one of three types of instructions at an origin (0), and also asked to return to the origin point without any help. The instructions include (I) having a topographical map of the area, (II) information about direction and distance to the destination, and (III) guided tours with the experimenter.