Location Tower

For college campuses, fairgrounds, amusement parks, and other large areas with many obstacles and heavy foot traffic:

A tower tall enough to be seen from practically anywhere in the area is erected. Atop this tower is a sphere covered with outward pointing tubes. At the base of each tube (printed on the sphere) is a coordinate in the form of, e.g., “14J”, with the numbers increasing clockwise around the tower and the letters increasing with altitude. Any point surrounding the tower can thus be described with a rough degree of accuracy by the coordinates visible from that point. For very large areas, multiple towers of different colors may be necessary.