The Trevi Fountain was designed by Italian architect Nicola Salvi and completed by Giuseppe Pannini and several others. The fountain has appeared in several notable films, including Roman Holiday, Federico Fellini's La Dolce Vita, the eponymous Three Coins in the Fountain, The Lizzie McGuire Movie, and Sabrina Goes to Rome.
The Vatican City is the smallest state in the world by both area and population. I recomend you to visit the Vatican museum, ask for the student discount, in there you will found the Capella Sistina.
I recommend visiting this city in summer, because you can take advantage of the beach and go surfing. If you are in Gijon you should go to the aquarium, Cimadevilla, el Molinon, try Asturian cider and fabada.