This quest was tough! I'm glad they are giving out the pin to everyone who completes it and not just top finishers because this one was a doozy. Random question and I hope it's ok to post but is the "American Waterfront" really at
Disneyland? THat was the only answer that worked for me after going through all four choices lol. I could have sworn I saw that at Disneysea though.
I found the first jewel on the upper left platform up the stairs kind of hidden near the beam. The rest were out in the open. Good luck on the quest, everyone!