Study abroad in spain or chile?

Next summer i will be leaving to study abroad for a year, i am 20 years old and a 2nd year in college. It is between spain and chile and i will have taken 6 years of spanish. I am very outdoorsy, i surf, ski, swim, backpack ect... so chile sounds awesome in that respect. However, i have heard great things about Spain as well. I really want to become 100% fluent in the language, and that is one of my biggest concerns. In Chile, i feel like it is sink or swim, they teach in spanish and only speak spanish, and i think i would really learn the language fluently there. In Spain i would have to learn the vosotros form of spanish, and it seems like it is more international and has more english speakers.. however, im not really sure if that is the case. If anyone is from spain or chile please let me know what you think!! talk to me about weather, things to do, traveling within europe/ south america, all the pointers you have. thanks!