Looking for a place that's right...

Hi! I am currently a Sophomore in High School, and I’ve been “preparing” to start looking at colleges for awhile. I believe that I am relatively intelligent. I have a 4.4 GPA and have taken all honors classes, and next year I will take 4 AP courses. I got a 31 on my first attempt at the ACT last year, and will continue to retake it – ideally attempting to get a 33 or 34. I have always considered, and have been encouraged, to look into universities like Brown (which may be a stretch) and Columbia, but I recently realized that I really want to study abroad and get out of the U.S. for all 4 years. Are there colleges where I can receive a good education that are American curriculums and outside of the U.S.? Is this a bad idea?