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."