When you come within 100 ft. of an active iris, you can determine where it is and when it will naturally close. Once per week, you can concentrate on this sensitivity for an hour to locate a nearby iris. If there is an iris within miles, you can guide yourself there as if by find the path for as long as the iris remains open.
Whether by inborn ability or experience with the plane, you to develop a sensitivity to the presence of irises; gateways into the mysterious Crossroads.