Hey Emie, In this type of context you can use either one, they both mean (to/in order to), however, you would probably see the latter more often. It is the statement of a simple fact. You are going to Spain to visit your family (a visitar). The first one is a little more specific, meaning that the purpose of your trip, is to visit your family. With the use of ''para'' you are saying: I'm going to Spain in order to visit my family. ex: Voy a la tienda a comprar frutas (to buy fruit) Voy a la tienda para comprar frutas (in order to buy fruit) Voy a la tienda porque necesito comprar frutas. (because I need to buy fruit) Also, "A" is commonly used to connect a verb to an infinitive, so in this case, that would be (voy) + a (visitar). Other examples would be: Comenzó a llover: it started raining Se negó a hablar. :)

"Voy a España a visitar (a) mis amigos." The explanation given by Sandrah. I can give no better explanation.