Going off to discover a whole new country doesn't necessarily mean hiring a car. If and where possible, try and choose public transport over a rental vehicle. Not only does this allow you to better respect the environment, but it also means that you'll have a greater chance to meet the local population. Trains are, for example, far less polluting than either the car or the plane, the means of transport which has the most devastating effect on the planet in terms of green house gas emissions. What's more, the train doesn't necessarily take longer to reach its destination than the plane. Take for example the route between Paris and Marseille in the south of France. When taking the TGV (high speed train) you arrive directly in the centre of town and don't have to go through all the security checks that you're obliged to encounter at the airport. The result is that the journey time ends up being roughly the same as if you'd taken the plane.