In Ibiza, we realized that to have any meaningful exploration, we needed a car. The clubs and everything else notable are spread out across the island. But to drive a car in Ibiza, and I'm sure in other foreign countries, you need an international drivers license.
Among the four of us and all our stuff, we were prepared to do anything from run the world to birth a baby, yet none of us had the foresight to obtain a foreign drivers license. It's safe to say that none of us had ever heard of such.