North Arrow is located in one of the point defining East Spiral. It is an astronomical instrument, pointer to the true north and parallel to the earth axis in both plan and elevation. Structurally North Arrow is a hinged pole: its alignment is maintained by a web of cables anchored to the ground. The cable-grid in plan view defines an arrow which points to the north as well. North Arrow points to the star Polaris and can function as a reference system to determine the celestial coordinates of a star in the northern hemisphere.
