OFFICE TREASURE HUNT

I am putting together a BEACH BASH for our office luncheon. We will be outside and would like to offer prizes. We will have a drawing for the "grand prize" but would like to have sort of a scavenger/treasure hunt for the smaller prizes. Need some ideas on how to do this. Do we use clues, ask questions and whoever answers the most questions wins a prize. HELP we are at a loss for ideas. Thanks.