Travelling is really the best way to learn a language. If you go with some previous learning, it's more profitable, of course, because you make more links and risk more, in the sense of exposing yourself to communication situations, but it's there, in the language environment, where you really take ownership of knowledge.
Besides this rooting and confidence acquisition, memorizing vocabulary becomes "natural", effortless. I have experimented that myself: many times I use words I simply have no idea howcome I know, words that are really specific, like "railings", or "scafoldings". Those ones I've learned visiting London just before the Olympic Games: there were "watch the scafoldings" signs everywhere, and the classical "don't attach your bike to the raillings", as well. I also had the opportunity to check pronunciation by travelling to different regions, testing my comprehension of accents, checking if people could really understand me by my speaking, and not only by my using body language. There were some ackward situations, of course, but those are really important experiences, although they got me embarrassed, because you never forget what has put you in trouble!