Diddy Kong Racing
First key: Go to Ancient Lake and stay to the right, not that far from the start/finsh line you will see a small ramp off in the grass with the key on top.
Second Key: The key for Sherbert Island is in Cresent Island. Take your car into the water & to the left and eventually you see an opening on the+ side of a rock, inside is the key.
Third Key: The snow key is directly behind the start finish line to your left. Go all the way around the track, right before you get back to the start finish line you will see an opening to the left. Take it and get the key!
Fourth Key: The key for Dragon Forest is in Boulder Canyon. Race your hovercraft utill you go over the draw bridge. Turn around pick up a couple of turbos and hop to hit the bell. The draw birge will raise up, Turbo your way back up the draw brige and you find the key at the top.