Find the yellow markers in the following locations:
-In Harbor City, the marker is hidden under one of the crates in the harbor behind big Willy's restaurant. -In Vietmahl, the marker is in the military encampment behind the ruins. -In Fairfield, the marker is next to the old power station in the corn field. Search until you find the yellow square. -In Fantasy Atoll, look in a hidden cave along the northern ridge of the "Sky God Cult."