this is a interest question,you can make a list to follow of that you want to do in your summer holiday.when i graduated from high school 8 years ago,most of the time ,i gone to travel riding an old bicycle around my hometown,that's was very funny,once i rode 100 miles away frome my house in a day time.how beautiful the spectacle is ,you can not image
what my suggestion is you can make an actual arrangement of your summer holiday and fulfill it.