My mom and I made a scavenger hunt for my niece when she was 7 or 8, her second trip. It was Christmas morning and she opened her presents to find, not only her presents, but little note cards with the letters to spell scavenger hunt. We told her that it spelled two words, the first being 9 letters and beginning with S and the second being 4 letters and starting with H. It took her a few minutes to figure the words and we did help a little.
After she realized what was going on, we told her she would need to find the answers to Who, How, Why, When and Where in her hunt. We gave clues to where the clues were hidden and she was off. When she got to the first spot, she saw a picture of the three of us(Who). The next spot had a small train(How). In the next area, she found birthday candles (Why) and then found a calendar with the date circled(When). I was sitting in the dining room with a tin foil covered cake pan with a note on it. She took the foil off and saw a giant cookie with the letters WDW written on it. At first she couldn't figure it out, so I went over all the clues with her and then reminded her that she hadn't figured out the last question, Where.
That was actually the hardest for her and so I told her it was the happiest place. She literally jumped up and down and then said, but we were just there so that can't be it. I shook my head yes that we were and she hugged me and cried, making me cry of course. It was the best reaction ever!